Stop Heat Illness Before It Becomes Serious

Heat illnesses - which occur primarily in summer in this part of the world - can range from a usually-harmless heat rash, to uncomfortable cramping, to the more serious heat exhaustion or even a possibly deadly heat stroke.

Our bodies usually cool us down by sweating, but when it's too hot or humid, or when people are in situations that put them at risk for overheating, the body's temperature control system can become overloaded.

Even when the outside temperature is fairly mild, high humidity can lead to problems - in fact, 70% of heat stress is due to humidity, 20% to the sun, and only 10% to air temperature.

Symptoms of heat illness often include fatigue, dizziness, headache, nausea, and confusion. High body temperature, changes in pulse or consciousness, and changes in sweat - especially when sweating actually stops - require immediate medical attention. Very high body temperatures can damage the brain or other vital organs.

Risk Factors
Although anyone can suffer from heat-related illness, some people are at greater risk than others. Infants and young children, older adults, and people who are sick, very underweight or very overweight are most likely to be affected. Exercising too much for your age and physical condition are also factors.

Other conditions that can limit the ability to regulate temperature include sunburn, fever, dehydration, high blood pressure or heart disease, disability, mental illness, poor circulation, or use of alcohol and certain drugs.

Children and Adolescents
Children are much more susceptible to heat illness than adults are. They absorb more heat and sweat less than adults. Since sweating cools the body, kids have a hard time lowering their body temperature.

The hotter the air temperature and higher the humidity, the more susceptible children and adolescents are to heat stress. Adults who are responsible for children - such as parents, caretakers, coaches, or camp counselors - need to be aware that children and teens cannot put up with as much exercise as healthy adults can.

Also, children are less likely to feel thirsty when they play or exercise for a long time; they need to be reminded to take regular breaks to cool down and drink fluids. A glass of cold water every 20 minutes or so is a good idea; occasional juice or sports drinks will help replace lost nutrients.

Older People
Older people are at high risk for developing heat-related problems because the ability to handle heat becomes less efficient with age. Illness, disease, and medications (including many of those for high blood pressure and heart disease) also increase this risk. Risk factors include:

• Age-related changes to the skin such as poor blood circulation and inefficient sweat glands.
• Heart, lung and kidney diseases, as well as any illness that causes general weakness or fever.
• High blood pressure or other conditions that require changes in diet, for example, salt restriction. Salt pills should not be used without first asking your health care provider.
• The inability to perspire caused by medications including diuretics, sedatives, tranquilizers, and certain heart and blood pressure drugs.
• Taking several drugs for various conditions. It is very important to continue to take prescribed medication and discuss possible problems with your health care provider.

Types of Heat Illness
In order of increasing severity, heat illness can lead to heat rash, heat cramps, heat exhaustion, and heat stroke. Here are their descriptions, symptoms, and treatments.

Heat Rash shows up as red, inflamed skin, often with tiny bumps. It usually occurs in parts of the body where heat and sweat are trapped by clothing - this is why babies often get diaper rash. It can be very itchy, but only gets worse if you scratch it.

The best treatment and prevention for heat rash is to keep the area very clean and dry. Don't use ointments and salves - the oils will just hold in the heat. Wear as little clothing as possible, shower often, and stay dry. For some people, baby powder can help.

Heat Cramps are muscle pains or spasms - typically in the abdomen, arms, or legs - that usually happen during exercise. People who sweat a lot are more likely to get heat cramps because they lose salt along with moisture, and low salt levels in the muscles cause the cramping. Heat cramps can also be a symptom of heat exhaustion. People who get heat cramps should:

• Stop all activity and sit quietly in a cool place.
• Drink clear juice or a sports beverage.
• Avoid exercise for a few hours after the cramps go away, because further exertion may lead to heat exhaustion or heat stroke.
• Seek medical attention for heat cramps if they do not stop in about one hour.

Heat Exhaustion (also called heat stress) often develops after several days of exposure to high temperatures with and inadequate fluids. Older adults, people with high blood pressure, and people working or exercising in a hot environment are more likely to experience heat exhaustion.

Symptoms of heat exhaustion include dizziness, weakness, nausea, headache, and cramps. The person with heat exhaustion might sweat heavily, become pale, and have cool, damp skin. Pulse rate can become fast and weak, blood pressure drops, and breathing becomes fast and shallow. Fainting is possible. People who might have heat exhaustion should:

• Drink cool, non-alcoholic beverages
• Rest
• Take a cool shower, bath, or sponge bath
• Find an air-conditioned environment and relax

Seek medical attention if fainting occurs or if symptoms worsen or last longer than one hour. If heat exhaustion is untreated, it could progress to heat stroke.

Heat Stroke is much more sudden and dangerous than heat exhaustion. In heat stroke, a person's body temperature rises above 105 degrees, they stop sweating and might become paralyzed or pass out. This means the body's heat regulating system is shutting down. Warning signs of heat stroke vary, but often include:

• Dizziness, nausea, faintness, staggering
• Throbbing headache
• Extremely high body temperature (above 103°F)
• Rapid, strong pulse
• Red, hot, dry skin (no sweating)
• Confusion, bizarre behavior, or combativeness
• Possible delirium or coma

Heat stroke is a medical emergency. It can cause brain damage, permanent disability or death or if emergency treatment is not provided.

1. Immediately move the person into a shady, cool, or air-conditioned space.

2. Dial 911 or call for emergency medical assistance. Cool the person by covering him or her with damp sheets or by spraying with cool water.

3. Direct air onto the person with a fan or newspaper.

4. Stay with the person until medical help arrives. Supply medical personnel with as much information as you can about the events leading to the emergency. If possible, give the patient's name, address, phone numbers, and emergency contact person.

Prevention
During hot, humid weather:

• Exercise less than normal for a week or so until you become adapted to the heat.
• When possible, limit outdoor activities during the hottest part of the day. Exercise during the cooler and/or less humid parts of the day, such as early morning or after the sun has gone down.
• Wear light colored, light weight, dry clothing. Heavy clothing will not help you lose any weight, just water. If clothes become wet, they should be changed for dry ones. A lightweight hat with a brim will give you extra protection from the sun.
• Drink plenty of non-alcoholic fluids, particularly water, before, during, and after exercising, whether you feel thirsty or not. Most people do not need extra salt because we get plenty in our diets. When exercising, two to four glasses of cool fluids each hour is usually enough. Sports beverages can replace the salt and minerals you lose in sweat. Liquids that contain alcohol or large amounts of sugar will actually cause you to lose more body fluid. Also, avoid very cold drinks, because they can cause stomach cramps.
• NEVER leave anyone in a closed, parked vehicle. This includes animals.
• Watch out for signs of heat illness (in yourself and others), such as pounding heart, shortness of breath, dizziness, weakness, fatigue, or confusion.
• Prevent sunburn. It causes a loss of body fluids, affects your body's ability to cool itself, and causes pain and damage to the skin. Apply sunscreen about 30 minutes before sun exposure; follow the label directions and apply more as needed.
• Take cool showers or baths, or move to an air-conditioned place to cool off. Electric fans can provide comfort, but when the temperature is in the high 90s, they will not prevent heat-related illness. Air conditioning is the strongest protective factor against heat-related illness.

People without fans or air conditioners should try to go to places like shopping malls, movies or libraries. If you don't drive, ask a friend or relative for a ride. To be a good friend or neighbor, offer rides to people who need them. Even cooling down for a few hours will help your system stay stable.

Many communities provide such services as cooling centers where people can go when heat and humidity become dangerous. Call your local Health Department to see if there are any heat-relief shelters in your area.

In Wisconsin, you can find the phone number for the nearest health department at the Wisconsin Local Public Health Department Listings web site.

To find any State Health Department listing, see the CDC's Public Health Resources page.

The National Weather Service has a Heat Index Chart that shows when heat and humidity can combine to create a dangerous situation.

This article includes information from The National Institutes of Health/MedlinePlus, the Centers for Disease Control and Prevention (CDC), and the Federal Emergency Management Agency (FEMA).

Each year, Medical College of Wisconsin physicians care for more than 180,000 patients, representing nearly 500,000 patient visits. Medical College physicians practice at Children's Hospital of Wisconsin, Froedtert Memorial Lutheran Hospital, the Milwaukee VA Medical Center, and many other hospitals and clinics in Milwaukee and southeastern Wisconsin.