Heat Exhaustion
Heat exhaustion is a heat-related illness that may occur after you've been exposed to high temperatures for several days and have developed
dehydration, which is an inadequate or imbalanced replacement of the fluids and
electrolytes you've lost through excessive perspiration.
Two types of Heat Exhaustion:
Water depletion. Signs include excessive thirst, weakness,
headache, and even loss of consciousness.
Salt depletion. Signs include
nausea and vomiting, frequent muscle cramps, and
dizziness.
Heat exhaustion is strongly related to the heat index, which is a measurement of how hot you feel when the effects of relative humidity and air temperature are combined. A relative humidity of 60% or more hampers sweat evaporation, which hinders your body's ability to cool itself.
The risk of heat-related illness dramatically increases when the heat index climbs to 90 degrees or more. So it's important -- especially during heat waves -- to pay attention to the reported heat index, and also to remember that the heat index is even higher when you are standing in full sunshine.
Age. Infants and children up to age 4, and adults over age 65, are particularly vulnerable because they adjust to heat more slowly than other people.
Health conditions. These include heart, lung, or kidney disease,
obesity or underweight,
high blood pressure,
diabetes,
mental illness,
sickle cell trait,
alcoholism,
sunburn, and any conditions that cause fever.
Medications. These include diuretics, sedatives, tranquilizers, stimulants, some heart and
blood pressure medications, and medications for psychiatric conditions.
People with diabetes -- who are at increased risk of emergency room visits, hospitalization, and death from heat-related illness -- may be especially likely to underestimate their risk during heat waves.
Without proper intervention, heat exhaustion can progress to heat stroke, which can damage the brain and other vital organs, and even cause death. Symptoms of Heat Exhaustion The most common signs and symptoms of heat exhaustion include:
confusiondark-colored urine (which indicates dehydration)dizzinessfaintingfatigueheadachemuscle crampsnauseapale skinprofuse sweatingrapid heartbeat Treatment for Heat Exhaustion
If you or anyone else has symptoms of heat exhaustion, it's essential to immediately get out of the heat and rest, preferably in an air-conditioned environment. If you can't get inside, try to find the nearest cool and shady place.
Other recommended strategies include:
Drink plenty of non-caffeinated and non-alcoholic beverages.Remove any tight or unnecessary clothing.Take a cool shower, bath, or sponge bath.Apply other active cooling measures such as fans or ice towels. If such measures fail to provide relief within 30 minutes, heat exhaustion can progress to heat stroke.
After you've recovered from heat exhaustion, you'll probably be more sensitive to high temperatures during the following week. So it's best to avoid hot weather and heavy exercise until your doctor tells you that it's safe to resume your normal activities.
Preventing Heat Exhaustion
When the heat index is high, it's best to stay in an air-conditioned environment. If you must go outdoors, you can prevent heat exhaustion by taking these steps:
Wear lightweight, light-colored, loose-fitting clothing, and a wide-brimmed hat.Use a sunscreen with a sun protection factor (SPF) of 30 or more.Drink extra fluids. To prevent dehydration, it's generally recommended to drink at least eight glasses of water, fruit juice, or vegetable juice per day. Because heat-related illness also can result from salt depletion, it may be advisable to substitute an electrolyte-rich sports drink for water during periods of extreme heat and humidity.Take additional precautions when exercising or working outdoors.The general recommendation is to drink 24 ounces of fluid two hours before exercise, and consider adding another eight ounces of water or sports drink right before exercise. During exercise, you should consume another 8 ounces of water every 20 minutes even if you don't feel thirsty. Avoid fluids containing either caffeine or alcohol, because both substances can make you lose more fluids and worsen heat exhaustion. If you have epilepsy or heart, kidney, or liver disease; are on fluid-restricted diets; or have a problem with fluid retention, check with your doctor before increasing liquid intake.