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Heat Stress

Heat-related deaths and illness are preventable, yet every year many people suffer heat-related illness when their bodies are unable to properly cool themselves. Very high body temperatures may damage the brain or other vital organs. Anyone can be affected, but older adults are more prone to heat stress than younger people for several reasons:

  • Elderly people do not adjust as well as young people to sudden changes in temperature
  • Many older people have a chronic medical condition that upsets normal body responses to heat
  • Some prescription medicines impair the body's ability to regulate its temperature or that inhibit perspiration


Heat stress is a dangerous physical burden which a hot environment can place on the body - especially the heart and blood vessels, an important part of the body's cooling system. If this burden is too great it can result in a number of serious, sometimes fatal, medical problems, including heat cramps, heat exhaustion, heatstroke, heart failure, and stroke. Heat stress can also aggravate existing diseases such as congestive heart failure.

Heat stress can occur under different conditions; it is not limited to heat waves or even to hot weather. It can occur on the job in places such as foundries, or in enclosed work places without adequate ventilation.

The body wages a struggle to maintain its temperature near 98.6 degrees F and actively resists the tendency of a very hot environment to raise its temperature above this. Excess heat is dissipated by increasing the flow of warm blood from the deeper parts of the body to the skin surface and by loss of body fluids through sweating. Sweat is the most important variable in this heat loss process because the evaporation of sweat carries away large amounts of heat.


A number of physical and environmental conditions increase the risk of experiencing heat stress and even developing serious or life threatening medical problems in hot weather. Any of the following physical conditions increase the risk:

  • Pre-existing heart disease
  • Emphysema/asthma
  • Previous stroke
  • Skin Diseases
  • High Blood Pressure
  • Problems with blood circulation
  • Infection or fever
  • Any weakening illness
  • Diabetes
  • Overweight
  • Sunburn
  • Diarrhea

A most critical environmental condition is humidity. Humidity greatly increases the risk of heat stress by directly interfering with the evaporation of sweat. Hot and humid weather is much more dangerous than hot, dry weather.

The use of certain prescription drugs which depress or interfere with the body's natural temperature control system can also increase your risk of suffering heat stress. If you take medicine for high blood pressure, nervousness, depression, poor blood circulation, or sleeping, ask your doctor or pharmacist for advice.


Here are some measures you can take:

(1) "Keep cool" - If you have air conditioning use it; and spend as much time as possible in cooler surroundings such as the coolest room in your home and air conditioned public places like libraries, shopping malls, movie theaters, and senior centers. Closing windows and drawing drapes or shades in the early morning prevents the daytime hot air from entering the home. Electric fans may provide comfort by circulating air, but when the temperature is in the high 90s, fans will not prevent heat-related illness. Taking a cool shower or bath or moving to an air-conditioned place is a much better way to cool off. Use your stove and oven less to maintain a cooler temperature in your home.

(2) "Dress against stress" - Wear as little clothing as possible when indoors. Wear lightweight, light colored and loose fitting clothes made of cotton rather than polyester as cotton breathes better than synthetic materials. Wear something on your head and over your neck to protect them from the sun. Sunburn affects your body's ability to cool itself and causes a loss of body fluids. It also causes pain and damages the skin. If you must go outdoors, wear a wide-brimmed hat along with sunglasses, and use sunscreen of SPF 15 or higher (the most effective products say "broad spectrum" or "UVA/UVB protection" on their labels).

(3) "Water use and abuse" - During hot weather, your body needs more water, so drink often and in reasonable amounts. Avoid too much coffee and tea - Water, fruit and vegetable juices are better. Slow down and take it easy, especially when the temperature has increased and your body isn't used to it. A cool bath or shower, water temperature around 75 degrees, provides relief from the heat. Cool water removes excess heat 25 times faster than cool air. Do not take salt tablets without a doctor's advice. Also, check with your physician before increasing the amount of salt or potassium in your diet during hot weather. Avoid alcohol entirely during heat waves. It can cause the body to lose important water and put a strain on the heart.

(4) "Watch what you eat" - Hot foods and heavy meals just add heat to the body. Avoid major cooking during the hotter part of the day. The amount heat generated by a kitchen stove can be substantial-it's safer and more comfortable to prepare meals during the cooler portion of the day.


Mild early warning signs of heat stress include: lack of energy, loss of appetite, and a slight feeling of nausea. Unless these symptoms persist, there's usually no need to worry. Just try to get cool.

If you experience any of the following SERIOUS signs during hot weather, seek medical attention:

  • dizziness
  • dry skin (no sweating)
  • breathing problems
  • diarrhea
  • vomiting
  • chest pain
  • extreme weakness
  • rapid pulse (heart beat)
  • nausea
  • throbbing headache
  • cramps

WATER - Drink to Your Health

Did you know?

  • Our bodies are about 2/3 (65%) water. After Oxygen, water is our most important requirement for survival.
  • Dehydration will kill faster than starvation. Losing 10% of our water can cause problems; losing 20% can be fatal.
  • Water helps maintain body temperature - perspiration keeps us cool and blood circulation keeps us warm.
  • Water helps in the digestion of food, carries nutrients through the body and waste out of the body, and lubricates joints and the spine. Water also helps prevent and relieve constipation, maintains adequate blood volume, and hydrates the skin.

We lose water through perspiration, excretion of urine and feces and evaporation from the skin and breath. Vomiting, diarrhea, bleeding and excessive sweating can lead to abnormal water loss and dehydration.

Symptoms of dehydration include:

  • Thirst
  • Dry mouth
  • Weakness
  • Dizziness
  • Dry, flushed skin
  • Rapid heartbeat
  • Headache
  • Constipation
  • Dark, strong smelling urine

How Much Water Do I Need?? Plenty of Fluids

Most people need SIX 8-ounce glasses of fluid each day. Some water also comes from foods we eat, especially fruits and vegetables. Water is the best thirst quencher. Other good fluid choices include fruit juices & fruit drinks, milk, and non-alcoholic and non-caffeine drinks (alcoholic and caffeinated beverages act as diuretics and can cause you to lose water). During hot weather you will need to increase your fluid intake, regardless of your activity level. Don't wait until you're thirsty to drink! During heavy exercise in a hot environment, drink two to four glasses of cool fluids each hour.

Warning: If your doctor generally limits the amount of fluid you drink or has you on water pills, ask how much you should drink while the weather is hot. Also avoid drinking very cold drinks quickly, because they can cause stomach cramps.

Other Tips During Hot Weather

To protect your health when temperatures are extremely high, remember to keep cool and use common sense. The following tips are important:

Replace Salt and Minerals

Heavy sweating removes necessary salt and minerals from the body. These must be replaced. If you must exercise, drink two to four glasses of cool, non-alcoholic fluids each hour. A sports beverage can replace the salt and minerals you lose in sweat. However, if you are on a low-salt diet, talk with your doctor before drinking a sports beverage or taking salt tablets.

Schedule Outdoor Activities Carefully

If you must be outdoors, try to limit your outdoor activity to morning and evening hours. Try to rest often in shady areas.

Pace Yourself

If you are not accustomed to working or exercising in a hot environment, start slowly and pick up the pace gradually. If exertion in the heat makes your heart pound and leaves you gasping for breath, STOP all activity. Get into a cool area or at least into the shade, and rest, especially if you become lightheaded, confused, weak, or faint.

Use a Buddy System

When working in the heat, monitor the condition of your co-workers and have someone do the same for you. Heat-induced illness can cause a person to become confused or lose consciousness. If you are 65 years of age or older, have a friend or relative call to check on you twice a day during a heat wave. If you know someone in this age group, check on them at least twice a day.

Do Not Leave People or Pets in Cars

Even in cool temperatures, cars can heat up to dangerous temperatures very quickly. Even with the windows cracked open, interior temperatures can rise almost 20 degrees Fahrenheit within the first 10 minutes. Anyone left inside is at risk for serious heat-related illnesses or even death. Children who are left unattended in parked cars are at greatest risk for heat stroke, and possibly death. When traveling with children, remember to do the following:

  • Never leave infants, children or pets in a parked car, even if the windows are cracked open.
  • To remind yourself that a child is in the car, keep a stuffed animal in the car seat. When the child is buckled in, place the stuffed animal in the front with the driver.
  • When leaving your car, check to be sure everyone is out of the car. Do not overlook any children who have fallen asleep in the car.

Hot Weather Health Emergencies

Even short periods of high temperatures can cause serious health problems. Doing too much on a hot day, spending too much time in the sun or staying too long in an overheated place can cause heat-related illnesses. Know the symptoms of heat disorders and overexposure to the sun, and be ready to give first aid treatment.

Heat Stroke can cause death or permanent disability if emergency treatment is not provided. Heat stroke occurs when the body is unable to regulate its temperature. The body's temperature rises rapidly, the sweating mechanism fails, and the body is unable to cool down. Body temperature may rise to 106°F or higher within 10 to 15 minutes. Warning signs of heat stroke vary, but may include:

  • Red, hot, and dry skin (no sweating)
  • An extremely high body temperature (above 103°F, orally)
  • Rapid, strong pulse
  • Throbbing headache
  • Dizziness
  • Nausea
  • Confusion, hallucinations, or aggression
  • Unconsciousness

If you see any of these signs, you may be dealing with a life-threatening emergency. Have someone call for immediate medical assistance while you begin cooling the victim. Get the victim to a shady area, and cool the victim rapidly using whatever methods you can. For example, immerse the victim in a tub of cool water; place the person in a cool shower; spray the victim with cool water from a garden hose; sponge the person with cool water; or if the humidity is low, wrap the victim in a cool, wet sheet and fan him or her vigorously. Monitor body temperature, and continue cooling efforts until the body temperature drops to 101-102°F. If emergency medical personnel are delayed, call the hospital emergency room for further instructions. Do not give the victim fluids to drink. Get medical assistance as soon as possible. Sometimes a victim's muscles will begin to twitch uncontrollably as a result of heat stroke. If this happens, keep the victim from injuring himself, but do not place any object in the mouth and do not give fluids. If there is vomiting, make sure the airway remains open by turning the victim on his or her side.

Heat Exhaustion

Heat exhaustion is a milder form of heat-related illness that can develop after several days of exposure to high temperatures and inadequate or unbalanced replacement of fluids. Those most prone to heat exhaustion are elderly people, people with high blood pressure, and people working or exercising in a hot environment. Warning signs of heat exhaustion include the following:

  • Heavy sweating
  • Paleness
  • Muscle cramps
  • Tiredness
  • Weakness
  • Dizziness
  • Headache
  • Nausea or vomiting
  • Fainting

The skin may be cool and moist. The victim's pulse rate will be fast and weak, and breathing will be fast and shallow. If heat exhaustion is untreated, it may progress to heat stroke. Seek medical attention immediately if any symptoms are severe, or the victim has heart problems or high blood pressure Otherwise, help the victim to cool off, and seek medical attention if symptoms worsen or last longer than 1 hour. Cooling measures that may be effective include: nonalcoholic beverages; rest; cool shower, bath or sponge bath; and an air-conditioned environment.

Heat Cramps

Heat cramps usually affect people who sweat a lot during strenuous activity because sweating depletes the body's salt and moisture. The low salt level in the muscles may be the cause of heat cramps. Heat cramps may also be a symptom of heat exhaustion. Heat cramps are muscle pains or spasms—usually in the abdomen, arms, or legs—that may occur in association with strenuous activity. If you have heart problems or are on a low-sodium diet, get medical attention for heat cramps. Stop all activity, and sit quietly in a cool place. Drink clear juice or a sports beverage. Do not return to strenuous activity for a few hours after the cramps subside, because further exertion may lead to heat exhaustion or heat stroke. Seek medical attention for heat cramps if they do not subside in 1 hour.


Sunburn damages the skin. Although the discomfort is usually minor and healing often occurs in about a week, severe sunburn may require medical attention. Consult a doctor if the sunburn affects an infant younger than 1 year of age or if fever, fluid filled blisters, and severe pain are present. Avoid repeated sun exposure. Apply cold compresses or immerse the sunburned area in cool water. Apply moisturizing lotion to affected areas. Do not use salve, butter, or ointment. Do not break blisters.

Heat Rash

Heat rash is a skin irritation caused by excessive sweating during hot, humid weather. It can occur at any age but is most common in young children. Heat rash looks like a red cluster of pimples or small blisters. It is more likely to occur on the neck and upper chest, in the groin, under the breasts, and in elbow creases. The best treatment for heat rash is to provide a cooler, less humid environment. Keep the affected area dry. Dusting powder may be used to increase comfort. Treating heat rash is simple and usually does not require medical assistance.

Information sources:

ERIE COUNTY DEPARTMENT OF HEALTH - BUREAU OF HEALTH EDUCATION AND INFORMATION, 95 Franklin Street, Buffalo, New York 14202 858-7690, "Heat Stress" 8/01

ERIE COUNTY DEPARTMENT OF SENIOR SERVICES - STAY FIT DINING PROGRAM, 95 Franklin Street, 13th Floor, Buffalo, New York 14202 858-8526, "Water - Drink to Your -Health" 2002