Hiking in Southern California, or any southwestern area of the US, can be challenging during the hottest months of the year. The radiation from the sun is being delivered at a more efficient angle, relative to the surface of the Earth, where we’re located. And the hot ambient air temperatures make it harder for our bodies to dump heat, as our muscles are generate it, while we move up the trail. Here are tips for hiking in the heat during these harsh months of 80, 90, and 100°F+ weather.
This article is actually about hiking in the heat
A lot of articles about hiking in the heat, preface their tips by telling you to not to hike in the heat.
They suggest heat avoidance behaviors like hiking at night, hiking early in the morning, and avoiding the 3pm hottest part of the day.
However, we’re all busy folks in So Cal, and we hike when we get to hike, often as part of a life routine, so most of this article will actually be about tips for hiking in the heat, when you can’t avoid doing so.
Choose you location wisely
Hiking in the shade
You can’t choose how hot the day will be, but you can choose how much solar gain will get absorbed into the surface of your body, by planning to hike in areas where there is shade.
For example, I have an article on hiking in the shade at Topanga State Park, where I guide you through the Deadhorse Trail, the Nature Trail, and the Deer Park in Topanga, which offers more forested shade than the average So Cal trail. Also check out my first leg of the Backbone Trail, going from the Deadhorse parking lot to the Fossil Ridge trailhead, which encompasses the shady Hondo Canyon Trail in some dense, forested areas of the Santa Monica Mountains.
The Angeles National Forest also provides nice shady trails, like those found at Santa Anita Canyon (when it finally gets around to opening back up).
Hiking near water
Coastal So Cal is often much cooler than the inland valleys. Go for trails that are washed in cool ocean air, like those in Malibu or Crystal Cove. See the Reef Point & Crystal Cove Trail at Crystal Cove State Park, for example.
Other water features, such as the streams and waterfalls, are prominent, again in the Angeles National Forest. I mentioned Santa Anita Canyon above, and not only is it shady from the forest canopy, but it has streams/waterfalls very close to most of its major trails.
Not only can these forest streams provide hydration if you have a Sawyer Squeeze filter, to filter out the bacteria in the water, but they can provide a medium for your body to rapidly cool down in, were you to experience heat exhaustion or heat stroke.
Hiking at altitude
Altitude can often provide a temperature differential sanctuary, relative to hikes near sea level. Further, altitude also affords a landscape of tall evergreen trees that provide significant shade to trails, as well as creeks, streams, and lakes.
I was at Big Bear Lake the other day. I hiked the Cougar Crest Trail up to the PCT, and the hiking was very pleasant, temperature-wise. Meanwhile, down in the San Fernando Valley, where I reside, the temperature was 15 or 20 degrees hotter.
Hiking on flatter trails
If you’re hiking merely for the scenery and to immerse yourself in nature, you may opt for easier trails to conquer, i.e. those with less strenuous uphill. That way your muscles aren’t generating as much heat, and warming up your core, past your body’s ability to thermoregulate.
Get acclimated to the heat before attempting challenging hikes
It can take a good 10 to 14 days of working/exercising outdoors to get acclimated to the heat. Once you are acclimated you should sweat more, and your sweat should have less sodium in it. The CDC has published the following tips for heat acclimatization:
Typically, acclimatization requires at least two hours of heat exposure per day (which can be broken into two, 1-hour periods). The body will acclimatize to the level of work demanded of it. Simply being in a hot place is not sufficient. Doing light or brief physical work in the heat will acclimatize you ONLY to light, brief work. More strenuous or longer tasks require more acclimatization. Stay hydrated! Dehydration reduces the benefits of heat acclimatization.
Heat Stress Acclimatization – Center for Disease Control
Personal heat acclimatization victory
I recently accomplished a 6.38 mile loop hike in Topanga State Park, going from Trippet Ranch to the Hub Junction near Cathedral Rocks and back, in the heat (85°F in the shade; 95°F+ in the sun). Average speed was 3.4mph with a total elevation gain of 1,221ft. I was out there a little less than 2 hours, but I sweated out around 2 liters of fluids – enough to thermoregulate on that highly sun exposed trail.
However, it took several failed attempts at hiking O’Melveny Park in 100-105°F weather to work up to that Topanga hike.
Higher sweat rate is key to heat acclimatization
Sweating is arguably the most powerful autonomic thermoeffector in humans. The potential heat loss provided by sweat evaporation results from a combination of the human body’s tremendous capacity to sweat and the latent heat of vaporization of sweat (2426 J per gram of sweat at 30°C (Wenger, 1972)). Maximal human sweat rates range between 1.5 and 2.5 L/hour, with some studies reporting values in excess of 3 L/hour (Torii, 1995). Assuming all of the sweat produced is evaporated, sweat rates of 1.5–2.5 L/hour can theoretically provide between 1000 and 1700 W of heat loss. This potential heat loss far outweighs what can realistically be achieved by dry heat exchange. For humans to lose a similar amount of heat through dry exchange would require standing outside, naked, in a 2 mph wind during the coldest day ever recorded in the United States (–80°F, Prospect Creek, AL, 1971)!
Chapter 13 – Sweating as a heat loss thermoeffector – Handbook of Clinical Neurology Volume 156, 2018, Pages 211-232
Measuring your sweat rate
Knowing your sweat rate, and monitoring it for an increase during heat acclimatization may help you figure out how heat tolerant you are when hiking.
Check out my article on measuring your sweat rate while on the trail, then measure your rate on day 1 and day 14 of your heat exposure to see if you are getting acclimated.
How much fluid to drink when hiking in the heat
In general terms, the amount of fluid to drink when hiking in the heat will be around 1 liter per hour (33 fluid ounces) for adults. But this really boils down to your personal sweat rate for the trail your on, and your underlying metabolic rate, which is based on your height, weight, and age.
You don’t have to try to replenish every drop of sweat you lose on the trail. All you have to do is drink enough to avoid dehydration, which puts you at risk for poor performance, or heat exhaustion and the dreaded heat stroke.
Usually just drinking when you’re thirsty will keep you from getting dehydrated, but it’s also a good idea to do scheduled drinks, especially if you’re going to be hiking hard for over an hour, and need a carbohydrate and electrolyte drink to keep you going, in terms of glycogen depletion.
After your hike, you can then drink 150% of your body water deficit created from sweating, over 6 hours, to fully rehydrate.
Related: for more info, check out my article, How Much Water Do You Need for Hiking?
Use a sports drink for heavy work that lasts an hour or more
Intense hiking that lasts over an hour starts to put a strain on glycogen supplies and increases sweat rate. During this type of condition the ISSN recommends consuming carbs at a rate of 30-60g per hour, by way of a 6-8% carbohydrate solution (Gatorade is a little over 6%) using 6 oz. every 15 minutes. (ISSN’s specific stance is 6-12 oz. every 10-15 minutes, but applying the maximal possible dosage under this formula may result in a overloading of carbs, at least by their stated dosing.)
Macronutrient Timing With Consideration to Hiking, Camp Hike Live California
It’s important to replenish electrolytes for high sweat volume hikes
If you’re sweating a lot on the trail, and only repleting the water and not the electrolytes, then that increases your risk of hyponatremia and its neurological maladies. So either bring a sports drink, an electrolyte powder to put into your water, or some salty snacks.
Check out my article How Much Sodium Do You Lose in Sweat and you’ll find the median athlete loses 830mg of sodium per liter of sweat. You don’t need to replete every last milligram you lose, but you do want to replete some of that if you’re on a longer, or high heat, sweaty hike.
I usually fill up my Nalgene with 1000mL of water, then on trail, once I’ve drank the first 500mL of it, I throw in an electrolyte powder or two for the next 500mL. The electrolyte powder I currently have in my pack is the SOS+ which has 330mg of sodium. I might use 2 or 3 packets for 2L of water. I don’t have any loyalty to that particular powder; it just happened be on sale at CVS when I was there one day.
Related: Also check out my article, Sweat, Mineral, and Micronutrient Losses Related to Hiking in High Temperatures, for a more in depth look at all your vitamins and minerals lost in sweat.
Clothing tips for hiking in the heat
Light colored clothes
Generally lighter colored clothing absorbs less infrared radiation from the sun than does its darker counterpart. That’s the type of solar energy that causes heat gain. However, again in general terms, darker colored clothing may block more ultraviolet radiation – the type that’s bad for your skin.
Pure white clothing is more apt to show dirt from the trail, so tans and khaki’s are likely your best bet.
UPF rated clothes
Clothing with high UPF ratings does indeed filter out a lot of UVA and UVB radiation. However, in order to achieve those higher ratings, these clothes tend to be thicker, and tighter woven.
High UPF rated shirts will have worse performance in extreme heat than a typical polyester base layer for hiking. For example my REI hiking base layer shirts are much cooler and comfortable in the heat, than my Columbia UPF 50 Bahama long sleeve shirts. And my REI shirts are black, while my Columbia shirts are white, tan, and light pastel blue.
However my main hiking/camping pants are the UPF 50 Columbia Silver Ridge Convertible Pants. These actually feel lighter, more airy, and have better moisture wicking performance than your typical jeans or cotton shorts. I wear them in extreme heat hiking all the time.
Some reasons you might want to wear UPF rated clothes include reducing risk of skin cancer; having light, sensitive skin that burns very easy; reducing risk of sun damage; having a sun allergy; and having a surgical scar that you want to fade back to your normal skin tone.
Polyester & polyester blend base layer shirts
Polyester naturally does do a good job at blocking UV radiation. But the main reason you’ll want to have a polyester, or high polyester content blended base layer shirt, is its ability to wick sweat and allow it to evaporate in an efficient manner.
Some folks will say cotton is okay for hot hiking as it retains moisture and gives the sensation of coolness against your skin. But let’s face it, if the moisture on your cotton shirt is already at body temperature, it’s not as efficient at taking the sweat and heat from your body and evaporating these into the air. Thus it’s not good at the only mechanism your body has at high ambient temperatures at cooling itself down. (At high temperatures your body cannot dump heat by means of radiation, conduction, or convection, and is wholly reliant on sweat evaporation to cool itself.)
Long sleeves vs. short sleeves
The main reason you’d want to go with long sleeves in high heat, is for sun protection. If you get a sunburn, this reduces your ability to thermoregulate your body properly.
Merino wool socks are okay for high temperatures
Merino wool is generally thought of as a cold weather base layer. However, if you wear a pair of light to medium weight merino wool socks that are ‘ankle’ or ‘quarter’ style, such helps minimize foot related sweat, and blister or hot spot formation, secondary to such.
Merino wool socks also help when you’re slogging through streams to cool off, because your feet don’t feel as ‘wet’ afterwards, as they would with cotton socks.
Light trail running shoes generally work better than heavy hiking shoes/boots
Light, quick drying trail runners work better in the heat than do hiking shoes or boots. Trail runners allow you to cool off by walking through creeks and streams, knowing that you can dry your shoes in a sunny spot during a lunch break.
Plus they’re just lighter and feel cooler, and work just as well as hiking shoes on non-technical trails.
Merino wool or polyester based underwear is also okay for hot hiking
Again the thin layers of merino wool or polyester blend fabrics that make up good hiking underwear are fine for hiking in the heat. Merino wool is a little softer, but polyester may be a little better for wicking sweat. Up to you really! I use both types that are REI brand they both work good for my hot summer hiking excursions:
Gear tips for hiking in the heat
Ventilated packs
If you’ve ever been to REI and looked at the Gregory or Osprey day packs, you’ve probably noticed that some have ‘free float’ suspensions, where the frame curves away from a trampoline mesh that is the part that touches your back, when you wear it:
My Gregory Zulu 30 backpack’s trampoline mesh is moisture wicking, and when paired with a polyester based summer base layer, it allows your back sweat to evaporate at a quicker pace. This does two things: it cools you faster as a lot of heat from your body is lost from the sweat evaporation process; anything that accelerates the process keeps you cooler. And it also keeps sweat from pooling on your back and running down into your pants and underwear.
Related: Check out my review of my Gregory Zulu 30 day pack by clicking here. There’s a link to the pack in the article if you’re interested in a cooler, less sweaty hike!
Use trekking poles only when absolutely necessary
Trekking poles are great for stability on steep terrain. They are also helpful in getting a better fat burning workout in as you hike, as you stress your triceps while using them.
However because you are activating your arm muscles when using them, that means extra heat generation from your body is occurring as you hike. If your legs are like a turning on a furnace when working them on climbs, then your triceps are like adding a space heater to the mix.
So just use your poles on the steeper uphill, the stream crossings, and slippery downhill, and store them all other parts of your hike.
Related: If you’re wondering how to attach your poles to your pack so you don’t have to always be carrying them when not in use, check out my article on just how to do that!
Use a Zoleo Satellite Communicator Device
A Zoleo satellite communication device lets you keep in touch with friends and family, even when there is no cell signal on the trail. It also has a check-in button on the device, and on the app, that when pressed tells your contacts your coordinates, and where to find you on a local map it includes in the message.
But more importantly, it also has an SOS button that lets you communicate with local authorities through a dedicated search and rescue hub. And when you hit the SOS your location is being transmitted to that S&R hub every few minutes.
If you’re solo hiking (or not), and start to experience heat exhaustion, which could lead to deadly heat stroke, the Zoleo could indeed save your life. Do not hesitate to press the SOS button if you are unsure of your outcome on the trail. Here in California, you won’t get a bill from Search and Rescue or the county your in, if you’re truly in need of rescue.
90% of the outdoor disaster stories I’ve heard about online all have the same thing in common. If the hiker or camper had only had a Zoleo with them, they’d still be alive today. So check out my review of my Zoleo Satellite Communicator. There is a link to the device’s Amazon page in the article.
Water filter
If you know you’re going to be near water, and want that insurance policy on not running out of your drinking water supply, then throw your filter in your pack. I personally have the Sawyer Squeeze, but you do you!
Heat index app
Make sure your weather app on your phone has a heat index calculator. The heat index factors in the humidity, which is a major variable on how efficiently you can evaporate sweat and thus remove heat from your body.
The OSHA-NIOSH Heat Safety Tool App is available on the Apple and Google app stores.
| Heat Index (°F) | Classification | Risk |
|---|---|---|
| 80 to 90 | Caution | Fatigue possible with prolonged exposure &/or active hiking |
| 90 to 103 | Extreme Caution | Heat cramps, heat exhaustion, and heat stroke possible with prolonged exposure &/or active hiking |
| 103 to 124 | Danger | Heat cramps or heat exhaustion likely, and heat stroke possible with prolonged exposure &/or active hiking |
| 125 or higher | Extreme Danger | Heat stroke highly likely |
Environmental Working Group safe sunscreens
If you want a list of sunscreens that are the safest for you and the waterways/ocean life, then check out my list of EWG top sunscreens you can buy off Amazon. I’ve even grouped them in the following categories: unscented for hiking and camping; vegan/cruelty free; those made with organic ingredients; and those made with all natural ingredients.
Health concerns when hiking in the heat
The four main health concerns when hiking in the heat, from mildest to worst case scenario are heat rash, heat cramps, heat exhaustion, and heat stroke. Sun related health concerns like sun burn and sun allergy also can be of concern, as these conditions reduce your ability to thermoregulate in the heat via sweating.
Nothing here should be construed as personal, comprehensive medical advise with guaranteed endpoints (medical outcomes). Consult your provider, or emergency services if needed, for personalized medical advise.
Heat rash
Heat rash occurs on hikers at places where their clothing rubs against their skin. This can also happen in skin folds. It’s more common in humid environments, thus it may be less likely in So Cal. Depending on the severity and the type of heat rash you have, the rash may be itchy.
- mild heat rash – small, clear bumps from pores clogged at the surface
- deeper heat rash – small, inflammatory bumps, with itch and prickling feeling; can fill with pus on occassion
- dermal layer heat rash – deepest form of heat rash with firm, flesh colored bumps that can have no other symptoms, or it can be itchy and painful.
Heat rash versus sun allergy
It’s important to differentiate heat rash from sun allergy.
Heat rash can take minutes to hours to develop, after you start sweating. It can resolve once your are in a cooler environment, but more severe cases may last 2 or 3 days. It happens in areas that are being occluded by clothing, skin folding, or an applied ointment.
A sun allergy, or allergic response to your skin’s chemical changes brought about by the stimulus of sunlight, takes hours to days to develop. And once it occurs it can take days to a week or more to resolve. It happens in areas of the skin exposed to sunlight, but the allergic response can also creep into less exposed areas. It can also occur under clothes with no UV radiation protection. Your skin can produce large clusters of hives that can merge together, depending on the severity. The itch can be extreme, and be worse at night when your cortisol levels tend to recede.
Heat rash treatment
The treatment for heat rash is just to remove yourself from the heat, and even take a cool shower, to discourage sweating. In the future, avoid oily sunscreens or sunblocks.
Sun allergy treatment
The treatment for sun allergy is to take an antihistamine, like Zyrtec (cetirizine), or Benadryl (diphenhydramine) on an around the clock basis, until symptoms resolve. Hydrocortisone cream, or prescription steroid creams like triamcinolone, betamethasol, or clobetasol, can also be warranted in more severe cases (devil’s itch, or hell’s itch).
Heat rash prevention
- maintain a healthy BMI to minimize skin fold occlusion.
- understand certain medications may increase your sweat rate, making you more vulnerable to heat rash: NSAID’s like ibuprofen and naproxen, SSRI’s like sertraline and citalopram, oral contraceptives, thyroid replacements like levothyroxine, antibiotics like ciprofloxacin, etc. (this is not a full list; consult FDA drug labeling for information on your particular medication), etc.
- Do not wear overly tight fitting clothing (that have tight areas in places you’ve had heat rash before).
- Do not use occlusive moisturizers (i.e. ointment based). Moisturizers with lanolin are okay, however, as this compound helps prevent clogged sweat ducts.
Heat cramps
Heat cramps are a result of intense hiking in the heat while not replenishing electrolyte losses from sweating. They are a sign of mild heat exhaustion, and should be interpreted that you are at significant risk of developing a more pronounced case of it.
That means immediately seek a cooler environment on the trail, whether it be shade or water, rehydrate with an electrolyte drink, or water and a salty snack, take in carbohydrates to increase muscle glycogen stores, massage the cramp out, and then return to your car and home, as soon as possible.
For cramps lasting an hour or more, it’s likely time to seek emergency care.
Heat cramps versus rhabdo
It’s important to distinguish between a heat cramp and a much more dangerous condition called rhabdomyolysis.
Heat cramps can occurs can happen in the arms, legs, core muscles, shoulders, or rib cage muscles. The cramps are muscle spasms lasting a few minutes (and up to 15 minutes). Sometimes you can actually see the muscle spasm. Moving to a cooler environment, massaging the cramp out, and repleting carbs and electrolytes will resolve these cramps, most of the time.
Rhabdomyolysis can occur regardless if it is hot out or not, but intense work in a hot environment, where electrolytes are out of whack, can help trigger it. Muscle pain is usually in the shoulders, lower back, and thighs (likely in the thighs for hikers). The pain is accompanied by muscle weakness. It won’t resolve on the trail through massage, or by simply moving to a cooler environment and repleting carbs and electrolytes.
Sometimes it’s a sign from muscle damage done the previous day or two; for example from a multi-day backpacking trip, where you don’t offer enough recovery time and nutrients for your muscles, between hiking events.
Your muscles are literally breaking down, and all the byproducts enter your blood stream and clog up your kidneys, making the condition life threatening. You may see dark or red/brown colored urine and notice a reduction in urinary output.
If that sounds like you, get to a cooler environment if you can, and hit the SOS button on your satellite communicator or phone. Stop or minimize the work on your painful muscles.
Heat cramp prevention
Start hydrated with an electrolyte sports drink. The National Athletic Trainers’ Association recommends the following pre-exercise hydration routine:
To ensure proper pre-exercise hydration, the athlete should consume approximately 500 to 600 mL (17 to 20 fl oz) of water or a sports drink 2 to 3 hours before exercise, and 200 to 300 mL (7 to 10 fl oz) of water or a sports drink 10 to 20 minutes before exercise.
National Athletic Trainers’ Association Position Statement: Fluid Replacement for Athletes
And keep your maintenance carbs/fluids/electrolytes going while on the trail. Again, as stated above, use 6oz. of a sports drink every 15 minutes during intense hiking.
Also avoid caffeine or alcohol, as they have diuretic effects that can lead to dehydration and/or electrolyte imbalances in the heat.
Heat exhaustion
Symptoms of heat exhaustion
Symptoms of heat exhaustion include:
- heavy sweating with cold, pale, clammy skin, and even goosebumps
- heat cramps/rash
- tiredness/weakness
- quick/shallow pulse
- rapid/shallow breathing
- nausea & vomiting
- headache
- irritability
- dizziness, light-headedness, blurred vision
- thirst
- fainting/orthostatic hypotension
- swollen hands, feet, or ankles
What to do if you experience heat exhaustion
If you are experiencing heat exhaustion on the trail and there is no close by shelter/shade from the heat or water source to use to cool your body down, hit SOS on your satellite communicator and let the rescue coordinator know you are unsure of your outcome. This is because if you cannot resolve your heat exhaustion, you could pass out and then progress to heat stroke as you literally bake under the sun.
Otherwise proceed directly to a cool place to dissipate your body heat, frequently sip water or sports drink, immerse yourself in cool water, or saturate your shirt and pants with cool water.
If your symptoms are getting worse, or if you cannot stop throwing up, or if your symptoms are still prominent after an hour of trying to cool off, you might do well in seeking emergency care.
Risk factors for heat exhaustion (and heat stroke)
Age: People under 4 have a lower sweat rate, undeveloped thirst response, higher surface area to body weight ratio and thus less ability to thermoregulate. People over 65 are more susceptible to dehydration, are often on medications that affect thermoregulation, and are more likely to have cardiovascular inefficiency (if not full on heart failure) that also makes it harder to control their temperatures properly in the heat.
Medication use: Beta blockers or calcium channel blockers can slow blood flow to the skin making it harder for your body to dump heat from its surface. Diuretics and alcohol increase your risk of dehydration. Tricyclic antidepressants, antispsychotics, and even anticholinergics (i.e. Benadryl, motion sickness tablets, GI cramping medications, bladder spams medications, etc.) reduce your ability the sweat. Stimulants like ADHD meds, cocaine, etc. can increase your core body temperature. Benzodiazepines (alprazolam, clonazepam, etc.) can interfere with the hypothalamus and cause heat intolerance.
Obesity: Excess insulation (fat) in and around your core makes it harder to regulate your temperature.
Heat naive: If you’re not yet acclimatized to the heat, you can’t sweat enough to lower your body’s temperature.
Ambient air temperature and heat index: See the risk levels in the heat index chart above, in the heat index app section.
Dehydration: If you can’t produce enough sweat to keep your body cool, then you’re at higher risk of overheating.
Wardrobe issues: Either dressing too warmly, or dressing with non-breathable clothes that down allow for maximal sweat evaporation.
Heat stroke
Symptoms of heat stroke
Symptoms of heat stroke include:
- pulse evolves from fast and weak in heat exhaustion, to fast and strong in heat stroke
- high temperature (103°F or greater)
- heavy sweating to the point of dehydration, then a stoppage of sweating
- hot, red, dry or damp skin
- nausea
- dizziness
- confusion
- losing or loss of consciousness
- headache
- seizures
- respiratory depression
What to do if you experience heat stroke
Call 911 or activate the SOS on your satellite communicator. Heat stroke in an emergency that can leave you permanently disabled or kill you. Your heat shock proteins that are trying to keep the structures of your cells together against the thermal energy that is pulling them apart, begin to fail.
Call out for assistance on the trail if you can.
If you surrender to an altered state of consciousness do not try to drink or let others give you fluids by mouth.
Get to a cooler environment if possible, away from direct sun exposure. Get in a stream or douse your clothes/body in cool water if possible. Remove extra clothing if possible and lay on your side to maximize your body surface area to the air.
Do not take fever reducer medication (acetaminophen, ibuprofen, aspirin).
If you are assisting someone in heat stroke, and have cold packs, place the cold packs all over their body. Spray them with, or dump cold water on them. Do everything you can to get their temperature to 102°F or below.
Heat stroke prevention
To prevent heat stroke, you have to prevent heat exhaustion and even heat cramps as these are all part of the same continuum of excess thermal energy loading into your body.
Again, read the pre-hike hydration routine from the NATA above, in the preventing heat cramps section.
Then, do your best to avoid dehydration on the trail by taking frequent drinks of fluid/electrolytes. Remember, in high heat, you need at least 1L of fluids per hour, but this need really comes down to your personal sweat rate, so be familiar with how much you sweat, before hitting the hot trail. Here is the link to my article on calculating your sweat rate. And of course bring enough hydration and electrolyte replacement for whatever you’re trying to tackle out there. Or have your water filter and electrolyte supplements at the ready.
Know your heat index, as mentioned in the app section above (under gear recommendations), and know where it will be during your hike. I’ve had multiple outings where I hit the trail in the morning, when it’s 85°F, and 6 miles later, it’s 100°F+. Once you get into the literal danger zone on the heat index classification table, that I published in that same area, it’s likely time to do minimal exertion hiking on shorter trails, and shade related hiking.
Know your trail. Know where the shade is, the water is, and where the exertion spots are. And get a plan going so you know where to go if you overheat.
Bring your Zoleo satellite communicator, and soon as you feel you aren’t recovering from heat exhaustion, and are unsure of your outcome, hit the SOS.
Be mindful of insects
It could just be the wet weather we’ve had last winter, that was favorable to insect populations, but I’ve noticed the bees and deer flies are out in full force during this July/August heatwave, in Southern California.
I’ve been bitten multiple times by aggressive deer flies both in Topanga State Park and in O’Melveny Park during 90 and 100°F+ weather we’ve had lately.
I’ve talked to another hiker recently, who was stung by a bee in Topanga State Park. She postulated that the bee went after her because of the smell of her perfume.
But really there are hives all over the forested areas of the park. A down tree with a hive in it is currently prohibiting traffic between Trippet Ranch and Musch Campground on the Musch Trail/Backbone Trail in the park. Another hive is positioned right across from where the Deadhorse Trail ends at Trippet Ranch, in a copse of trees.
Also, it seems like bees or yellow jackets are always hanging out at water fountains, on or around the trails, so take care that you are free to drink, and not about to grab a thirsty wasp, when using such water sources.
Keep in mind that DEET insect repellents don’t work on aggressive bees, but they do work against deer flies. And if you don’t want to put DEET on your skin, just spray it onto a handkerchief and tie it around your arm.
Also you may opt for fragrance free sun blocks to minimize insect attraction. Check out my fragrance free sun protection picks, that are Environmental Working Group safe selections, for your health, and the environment, by clicking here to read the article.
Hiking in the heat FAQ’s
How to keep hands from swelling when hiking in the heat?
Due to the vasodilation effect in you skin, where your arteries dilate to make your body more efficient at moving and dumping heat, your hands might swell when hiking in hot temps. As your arteries dilate, they become more leaky, and fluid from the blood stream leaks into the surrounding spaces.
If you don’t like your hands swelling when hiking, you can bring trekking poles, set at the correct height, such that your hands remain elevated, enough that gravity cannot cause pooling of this extracellular fluid.
References
- Heat Rash – Mayo Clinic
- Heat Rash – Mayo Clinic – diagnosis, treatment, self-care
- Miliaria
- Drug-induced hyperhidrosis
- The Most Common Medications that Cause Secondary Hyperhidrosis
- Sun allergy – Mayo Clinic
- Heat Cramps – Cleveland Clinic
- Heat cramps from exercise?
- Rhabdomyolysis – Cleveland Clinic
- Warning Signs and Symptoms of Heat-Related Illness
- First Aid for Heat Stroke – My Health, Alberta
- Heat Exhaustion – Mayo Clinic
Further Reading
Thanks for checking out my article on hiking in the heat! Now check out my main page for more topics on hiking, camping, and the gear that makes these happen.
See ya out there…