Heat Related Illnesses In The Wilderness ~ Summer Is Coming!

White Tank Mountains Regional Park.

Heat Related Illnesses  –  Just like almost every other year, summer is creeping up quickly, and prevention of heat related illnesses should always be on the mind.  There are several things that a person can do to prevent heat related illnesses.  Here are a few:

  • Adventure really early in the morning; perhaps even before sunrise.
  • Give your body a chance to acclimatize to hotter conditions; building up the time spent in hotter conditions a little at a time.
  • Wear appropriate clothing – synthetic materials that will wick away sweat from the skin and dry quickly.
  • Increase water intake the evening before, as to not risk starting your adventure already dehydrated. (Caffeine contributes to dehydration.)
  • Bring sliced cucumbers as snacks as they have a high water content.
  • When possible, choose adventure sites that offer intermittent to mostly shaded trails.
  • Wear breathable head cover with a full brim.
  • Wear a cooling scarf.
  • Bring plenty of water

So here is a cool bit of information, for the folks like me, who think the functions of the body are amazing.  The main way that the body puts off heat is through what is called “radiation”.  The body can open up the blood vessels (dilate) to let more blood flow in while it increases the rate that the heart pumps the blood through the body. This radiates more blood to the surface of the skin, where the heat can leave the body.  When the body is really hot, it can increase the blood flow to 4L/minute!  Keep in mind though; when it is hotter outside the body than inside the body, the process is basically reversed, and the body will take in the heat.

Hendrix taking in the view on a break while hiking in the White Tank Mountains Regional Park.

Another way the body puts off heat is by sweating AND evaporation.  These two things go together.  This is where the right clothing helps instead of hinders.  If you are wearing clothing that traps the moisture of sweat against the body, and the moisture is not able to evaporate, you are basically trapping in the heat.  As stated above, you want to wear clothing that pulls the moisture away from the skin. *While not discussed in this post, it is also important to wick moisture away from skin in the winter also. 

There are a few things that can make a person more susceptible to heat related illnesses.  While a very young person’s ability to regulate temperature may not be completely developed yet, an elderly person’s ability may no longer work as well.  Recent consumption of alcohol, lack of sleep, and certain medications can also make a significant contribution to heat related illnesses.

So, what are heat related illnesses?


When blood is pumped to the skin (shunted) it can decrease the blood to the brain and syncope can occur.

Signs and symptoms (S/S): tunnel vision, dizzy, nausea, sweating, and weakness

Treatment (TX):  Lie down in the shade, with feet elevated.  Rest and hydrate.  When feeling back to normal, proceede with caution, continuing to hydrate and taking breaks.  Consider calling it a day.


While not completely clear on why these cramps occur, it is possible it is related to the loss of too many electrolytes (sodium, potassium, calcium).  Cramps can occur in the abdomen, calf, and thigh muscles and are painful.

TX:  Rest in the shade.   If salt is available, mix a 1/2 teaspoon in a liter of water and slowly drink.  If available, chew 2 Tums for calcium replacement.  If symptoms persist, or return, it is advisable to head for the house, and perhaps seek medical care.  *Take note that when drinking water with salt, it is necessary to not reintroduce salt too quickly, so not guzzling is important.  

Hendrix using the shade to cool off. Hendrix is also exposing his under belly to the cool dirt to cool off.


Somewhat vague term; an inability to cope with the stress of heat.  It may, or may not, be an early stage of heat stroke (discussed next).

S/S:  Heart rate faster, breathing faster, skin is pale, cool, and clammy, cramps, headache, nausea, weak, tired, temperature normal or only slightly elevated.  **Take note that with heat exhaustion, a person is generally still alert and knows what is going on.

TX:  Lie down in shade, preferably flat.  Remove excess clothing. Hydrate, if possible, with 1 Liter of water with a teaspoon of salt; drinking slowly.  If not, give a sports drink, if available.  Person will usually recover from heat exhaustion when well cooled and hydrated.  Don’t rush this, to get back on the trail.  Take the time needed to fully recover.   With that said, ending the adventure at this point, is not a bad idea.  If choosing to continue on, it is definitely advisable to do so slowly, and STOP and seek medical attention if symptoms re-appear.


MEDICAL EMERGENCY –  If body temperature reaches approximately 104 degrees, or higher, it is at risk of a heat stroke.

S/S:  All of the same s/s listed above for heat exhaustion, with 2 exceptions;  temperature is high and person is disoriented.  This person is altered mentally.  Irritability and difficulty walking.

TX:  This person needs to be taken to the hospital asap.  Immediate cooling is also important.  Place out of the sun, or hot environment, remove clothing while providing as much privacy as possible, wet the body and fan to speed up the evaporation of water, apply cool wet cloths under armpits and groin areas.  If can be done safely for all involved, placing person in cool water is helpful.  If medical treatment is not available asap, monitor the person’s temperature, as to not cool the person too much.  If temperature comes down, discontinue cooling treatment; however continue to monitor for a rebound elevation of temperature.  THIS PATIENT NEEDS TO GO TO THE HOSPITAL, EVEN IF TEMPERATURE COMES BACK DOWN! There can be organ damage that is not easily detected in the wilderness.

What About The Dogs

Hendrix is obcessed with water, and especially in hotter months, we try to adventure as close to water as we can get.

Do you hike with your 4 legged friends?  Our dogs are at risk of heat related illnesses also!  Prevention is imperative! Most of the information in this post will apply to dogs also.  Especially when adventuring with dogs in hotter months, choosing places with a lot of access to water will help prevent heat related illnesses in our dogs.  There are also several options in the way of gear for the dogs and can be researched and purchased here.

Have you had any heat related illnesses that you want to tell us about?  Or any other thoughts you want to share?  Please add comments below!  We all can learn new information and we all can teach each other!

*For those of you that do not know, I am an RN.  I have practiced in an ICU/Emergency Room setting for the majority of my almost 12 years of being a nurse.  I have completed my Wilderness Upgrade For Medical Professionals in 2016, with the National Outdoor Leadership School (NOLS).  Content for these posts are obtained from my nursing training/practice, and training from my WUMP certificate.  In an attempt to make wilderness medical situations/emergencies just a little less scary and/or confusing for those who don’t have medical training, I am going to periodically put out “Monday’s Medical Moment” posts. Posts will be for basic information only.  Care and treatment by a medical professional is not to be replaced by this post.  

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