Hyperthermia
Avoiding, Recognizing and Effectively Treating It
Hyperthermia is a state of elevated body temperature caused when the body generates or is exposed to more heat than it can handle, overwhelming the body's regulatory mechanisms and potentially leading to serious injury or death.
Much attention has been given to hikers experiencing hypothermia, when the core body temperature falls to dangerous levels. However, many hikers fall victim to hyperthermia every year. When this condition is not recognized and treated quickly, it can become life threatening.
Symptoms of someone experiencing heat related illness include:

- hot, dry, red skin
- rapid breathing
- elevated heart rate
- decreased blood pressure
- dizziness
- fainting
- nausea
- muscle cramps
As this abnormally elevated body temperature worsens, the body will lose the ability to sweat. This is an advanced state requiring immediate medical attention.
How to Avoid
Avoiding hyperthermia starts before a hiker leaves home with trip planning. Research the area where you will be hiking. Is there shade available? Is water plentiful? Can postponing the trip by a week or two offer some relief from extreme temperatures?
If you find yourself hiking in extreme heat and humidity, take the following precautions:
- Drink plenty of fluids

- Avoid large amounts of caffeinated beverages as they have a tendency to aid in dehydration
- Eat frequently and in smaller quantities
- Wear light colored, loose-fitting clothing and a wide-brimmed hat
- Take frequent breaks in areas protected from direct sun
- Hike earlier in the day and late in the evening, resting during the hottest part of the day
Now What?
If you find yourself or your hiking partner experiencing symptoms of heat related illness, immediately stop your hike and begin aggressively treating the affected hiker to lower the body temperature. Fever reducing medications such as aspirin, tylenol and ibuprofen will not have any affect on hyperthermia.
Instead, move the hiker to an area protected from the sun...even if that means erecting a temporary shelter for shade.
Relieve the hiker of his pack, loosen and remove unnecessary clothing to expose the skin to the air. Obtain cool (not cold) water and begin sponging the water over the head, neck and chest.
If the hiker is conscious, begin giving cool water to drink. Don't encourage gulping of large amounts of water quickly as this may cause vomiting, which worsens the condition.
If there is a cool spring or other water source nearby, the hiker can sit in the stream, pouring water over the body. This will quickly bring the body temperature down.
If the water is so cold as to make the hiker shiver, do not use this method. Shivering is the body's way of generating heat and is counter-productive to what you are trying to accomplish. Also, very cold water will cause the blood vessels to constrict, holding in the heat you are trying to dissipate.
Hyperthermia, if caught early can be treated and corrected. The hiker experiencing hyperthermia will be weak and tired after the experience. A long rest period, perhaps a whole day is appropriate.
Dispel a Myth
You may have heard it said that "when you begin to feel too hot, take a break, drink fluids."
Let me explain that you will NOT feel the effects of an elevated core temperature "coming on." They present suddenly. You will be seemingly fine one minute and close to collapse the next.
Therefore, the wise hiker will take precautions whenever climate conditions produce extreme heat and humidity. Please do not wait until you "feel too hot" to take action. At that point, you are well into heat exhaustion and in need of the help of others.
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