Heat Exhaustion & Heat Stroke – When to be Concerned

As temperatures rise all over the country, so does the risk of heat related illness; especially for those who are outdoors engaging in strenuous physical activity. Before you head out into the heat, make sure you are adequately prepared; dress appropriately for the weather conditions, stay hydrated and protected from the sun.

Take a few minutes today to refresh your understanding of heat related illnesses. Know the signs and symptoms so you know when you can treat problems on your own and when you need to go for help.

Heat Exhaustion

Heat exhaustion is caused by dehydration as a result of exposure to high temperatures for several days. Heat exhaustion is not a life threatening condition, but should be taken very seriously. If left untreated, heat exhaustion can progress to heat stroke, which can be life threatening.

There are two causes of heat exhaustion:

  • Water depletion: Symptoms include extreme thirst, weakness, headache and in some cases, loss of consciousness.
  • Salt depletion: Symptoms include nausea, vomiting, muscle cramps and dizziness.

The most common signs and symptoms of heat exhaustion include:

  • Confusion
  • Dark-colored urine (a sign of dehydration)
  • Dizziness
  • Fainting
  • Fatigue
  • Headache
  • Muscle cramps
  • Nausea
  • Pale skin
  • Profuse sweating
  • Rapid heartbeat

If someone in your group is experiencing signs or symptoms of heat exhaustion, it is essential to immediately stop all physical activity, get out of the heat and into a cool, shady place.

  • Hydrate with electrolytes. This can be water along with some fruit or trail mix, a sports drink or even a homemade electrolyte solution. Avoid caffeine and alcohol because they will cause further dehydration.
  • Speed the cooling process by removing restrictive or unnecessary clothing, applying cool cloths and fanning the patient. Place cold packs or cool cloths on the head and neck and in the armpits and groin area to facilitate cooling. If possible, have them take a cool shower.

This treatment should provide relief of symptoms within 30 minutes. However, the patient needs to rest a full 24 hours to recover. Keep in mind that a person who has suffered from heat exhaustion will be more susceptible to it in the future, especially within the next few days. So, it is best to take it easy and avoid strenuous activity in the heat for at least a week.

If the treatment does not provide relief of symptoms, the patient should be evacuated and seen by a doctor.


Heatstroke is also a heat related illness caused by exposure to high temperatures for a prolonged period of time or by physical activity. It occurs when a person becomes dehydrated and overheated, which the body temperature climbing to 104 degrees or more. is a serious condition that can result in damage to the brain, heart and kidneys, or even death. Risk of heatstroke is greater for young children and elderly adults.

  • Confusion (may have difficulty speaking & hallucinations may occur)
  • High Body Temperature (over 104 degrees)
  • Dizziness
  • Fatigue
  • Headache (throbbing)
  • Muscle cramps & weakness
  • Nausea & Vomiting
  • Red, Flushed skin
  • Lack of Sweating
  • Rapid Heartbeat
  • Rapid Breathing
  • Unconsciousness (can result in coma or even death)

The clearest difference between heat exhaustion and heatstroke are the skin color and sweating. When a person is suffering from heat exhaustion, they generally will look pale and will be sweaty. However, if they progress to heat stroke, the sweating mechanism fails and the skin becomes red as the body pushes blood to the surface of the skin in an effort to cool it down.

Heatstroke is a life-threatening condition! If you think a person is experiencing heatstroke, immediately evacuate them from the back country and ensure they get medical attention. It is essential to actively hydrate the patient. Be careful not to cool the patient TOO quickly, however! If the patient begins to shiver, this will cause an increase in internal temperature, which increases danger to the patient.

As always, the best treatment is prevention! The best way to prevent heat exhaustion or heat stroke is to stay adequately hydrated, which can be a challenge during strenuous activity in high heat. Luckily, there are numerous products on the market that can help you maintain safe hydration levels. Make sure to eat well and dress appropriately for the weather, take plenty of breaks to cool down and get adequate rest. At the first sign of heat exhaustion, it is best to stop, cool down and rest for 24 hours. It is better to lose a few hours of your trip to rest than to have to cut it short due to illness or injury! If you are planning to be outdoors this summer, consider taking a Wilderness Medicine course from SOLO Southeast to help prepare yourself. In our courses, you will learn how to identify and treat the most common illnesses and injuries that occur in the outdoors and you will know when you need to seek help. Having this knowledge will help you have a safer, more enjoyable outdoor experience.


  1. Krystal Clark on May 4, 2020 at 7:41 pm

    How can I recover from heat exhaustion after a year? I still have symptoms/ side effects when I’m in the sun for 5-10minutes. I’ve been trying to hydrate before going out but it doesn’t seem to work. My body temp goes up, I have a fever, am dizzy and very fatigue. I suffered from heat exhaustion while riding my bike in temps of about 101.

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