Sweat acts like our natural air conditioner. As sweat evaporates from our skin, it cools us off. Our personal cooling system can fail, though, if we overexert ourselves on hot and humid days. This can result in heat exhaustion or a heat stroke, which is life threatening.
Heat exhaustion takes time to develop. Fluids and salt are vital for health. They are lost as children and adults sweat a lot during exercise or other strenuous activities. It is very important to drink lots of non-alcoholic liquids before, during, and after exercise in hot weather. As strange as it seems, people suffering from heat exhaustion have low, normal, or only slightly elevated body temperatures.
Signs and Symptoms
Signs and symptoms of heat exhaustion include:
Cool, clammy, pale skin
Sweating
Dry mouth
Fatigue, weakness
Dizziness
Headache
Nausea, sometimes vomiting
Muscle cramps
Weak and rapid pulse
Signs of heat stroke include:
Very high temperature (104o
F or higher)
Hot, dry, red skin
No sweating
Deep breathing and fast pulse, then shallow
breathing and weak pulse
Dilated pupils
Confusion, delirium, hallucinations
Convulsions
Loss of consciousness
Heat stroke, unlike heat exhaustion, strikes suddenly, with little warning. When the body's cooling system fails, the body's temperature rises fast. This creates an emergency condition.
A chronic medical condition such as diabetes, use of alcohol, and vomiting or diarrhea can put children and adults at risk for heat stroke during very hot weather. Heat stroke in children is not only due to high temperatures and humidity, but also to not drinking enough fluids.
Prevention
Heat exhaustion and heat stroke can be prevented if you:
Do not stay in or leave anyone in
closed, parked cars during hot weather.
Use caution when you must be in the sun. At
the first signs of heat exhaustion, get out of the sun or your body temperature will
continue to rise.
Do not exercise vigorously during the
hottest times of the day. Instead, run, jog, or exercise closer to sunrise or sunset. If
the outside temperature is 82oF or above and the humidity is high, do your
activity for a shorter time.
Wear light, loose-fitting clothing, such as
cotton, so sweat can evaporate. And put on a wide-brimmed hat with vents.
Drink lots of liquids, especially if your
urine is a dark yellow, to replace the fluids you lose from sweating. Thirst is not a
reliable sign that your body needs fluids. When you exercise, it is better to sip rather
than gulp the liquids.
Drink water or water with salt added if you
sweat a lot. (Use 1/2 teaspoon salt in 1 quart of water.) Sport drinks such as Gatorade,
All Sport and PowerAde are good, too.
If you feel very hot, try to cool off. Open
a window, use a fan, or turn on an air conditioner.
Limit your stay in hot tubs or heated
whirlpools to 15 minutes. Don't use them when you are alone.
Do not drink alcohol or beverages with
caffeine, because they speed up fluid loss.
Stay out of the sun if you are taking water
pills (diuretics), mood altering, or antispasmodic medications. Check with your doctor
which medicines are safe for you to use.
Do not bundle a baby in blankets or heavy
clothing. Infants don't tolerate heat well because their sweat glands are not well
developed.
Some people perspire more than others.
Those who do should drink as much fluid as they can during hot, humid days.
Know the signs of heat stroke and heat
exhaustion and don't ignore them.
Are any signs of heat stroke present?  Body temperature 104o F
or higher Skin that is red, dry, and/or hot Pulse that is rapid and then gets weak No sweating Confusion, hallucinations, loss of
consciousness, or convulsions{Note: Do CPR if the person is not breathing and has no pulse. (See CPR.) Do rescue breathing if the person is not breathing but does have a pulse. (See Airway and Breathing under "CPR".) See also First Aid Before Emergency Care under Self-Care Tips below.}  |
 |
| Does the person have any of these signs? Too dizzy or weak to stand Non-stop vomiting Pale, cool, and clammy skin {Note: See First Aid Before Emergency Care under Self-Care Tips below.} |
|
| Are 2 or more of these signs of heat exhaustion present? Dry mouth Fatigue and weakness Headache Nausea Weak and rapid pulse Muscle cramps Feeling lightheaded or faint |
 |
First
Aid Before Emergency Care
It is important to
lower the body temperature. To do this:
Move the person to a cool place indoors or under a shady tree. Place the feet higher than
the head.
Remove the clothing and either wrap the person in a cold, wet sheet, sponge the person
with
towels or sheets that are soaked in cold
water; or spray the person with cool water. Fan the
person. If using an electric fan, use caution.
Make sure your hands are dry when you plug the
fan in and turn it on. Keep the person with
wet items far enough away from the fan so as not to
cause electric shock.
Put ice packs or cold compresses on the neck, under the armpits, and on the groin area.
Place the person in the recovery position
once his or her temperature reaches 101oF. (Do not lower the temperature
further.) (See Recovery Position.)
First Aid For Heat Exhaustion
{Note: These apply to you or anyone else who has
heat exhaustion.}
Move to a cool place indoors or in the
shade.
Loosen clothing.
Take fluids such as cool or cold water. If
available, add 1/2 teaspoon of salt to 1 quart of water and sip it, or drink sport drinks
such as Gatorade, All Sport, or PowerAde.
Have salty foods such as saltine crackers,
if tolerated.
Lie down in a cool, breezy place.
HEALTH AT HOME - Your Complete Guide to Symptoms, Solutions, and Self-Care © 1999 by Don R. Powell. American Institute for Preventive Medicine.
Date updated 04/21/99