The stages of heat illness
When talking about temperature regulation in the heat, there are a few things you need to be aware of about temperature and humidity.
The body’s main defense against rising internal temperatures is to sweat.
The evaporation of the sweat off the skin cools the body off.
An issue occurs with this process when the temperature and/or the humidity are high enough that sweat does not evaporate.
At around 60 percent humidity, evaporation is inhibited, and around 80 percent humidity it stops altogether.
The most common dangers of exercising in the heat are dehydration from excessive sweating, and hyperthermia either from your body running out of sweat, or the humidity being so high that the sweat does not evaporate. It is important to stay well hydrated! When your body becomes excessively dehydrated, blood volume decreases so much that the circulatory system can stop working. When the body cannot cool itself down, due either to dehydration, or a too high level of humidity not allowing the water to evaporate, heat illness can occur.
The most important thing to know is that heat illness is not an all or nothing event but a progression that leads to increasingly more severe consequences to your health. The following breakdown explains in detail the four levels of heat illness, each level compounding on the next
Stages of heat illness
Stage 1: Heat syncope
Signs and Symptoms
Headache and / or
Nausea
Immediate Care Strategies
Normal intake of fluids with electrolytes
Stage 2: Heat Cramps
Signs and Symptoms
Skin: flushed, moist
Temperature: Normal or slightly elevated (less than 102.5)
Other symptoms: painful cramps, especially in the legs
Immediate Care Strategies
If cramps are isolated:
Gentle stretching of affected muscle
Rest in a cool place and drink a sports drink, which has electrolytes and salt, or drink cool water.
If cramps are severe: follow heat exhaustion protocol
Stage 3: Heat Exhaustion
Signs and Symptoms
Sweating: Profuse
Skin: Cold, clammy and pale
Temperature: Normal or slightly elevated (less than 102.5)
Heartbeat: Weak but rapidly beating
Breathing: Shallow
Other symptoms: Dizziness and or Nausea, possible Loss of consciousness
Immediate Care Strategies
Place in supine position with feet elevated 12-18 inches
Gentle massage of extremities
Force fluids
Monitor body temperature and other vitals
Refer to physician
Stage 4: Heat Stroke
Signs and Symptoms
Sweating: None
Skin: Very hot , dry, either red or a ashen in darker pigmented skin
Temperature: as high as 106
Breathing: Labored, even in a semi reclined position
Immediate Care Strategies
This is an extreme medical emergency - seek medical attention ASAP
Strip individual down to undergarments
Cool quickly starting with the cheat and continuing down the body, (use ice, water, and or fans)
Wrap in cold wet sheets for transport
Treat for shock, if breathing is labored place in semi-reclining position.
While this information is essential in being able to recognize the signs and symptoms of heat illness, the best strategy is always prevention. Stay tuned, next week we will discuss those strategies in detail!
Information collected from E.T. Howley and B.D. Franks, Health/Fitness Instructor’s Handbook. 3rd ed. Copyright 1997 Human Kinetics Publishers, Inc
