Best Methods for Surviving
Heat-Wave Disasters...

Surviving Heat-Wave Disasters by Proper Planning and Preparation.

A "heat-wave" or extreme heat situations arise when waves of heat occur during a prolonged period of excessive heat, often combined with excessive humidity. Extreme heat, usually known as heat-waves, kill by pushing the human body beyond its limits of temperature and hydration balance.

In extreme heat and high humidity, evaporation is slowed and the body must work extra hard to cool itself and maintain a normal temperature.

How Heat Affects the Body

Most heat disorders occur because the victim has been overexposed to heat or has over-exercised for his or her age and physical condition. Older adults, young children, and those who are sick or overweight are more likely to succumb to extreme heat.

Human bodies dissipate heat by varying the rate and depth of blood circulation, by losing water through the skin and sweat glands, and -- as the last extremity is reached -- by panting, when blood is heated above 98.6 degrees. The heart begins to pump more blood, blood vessels dilate to accommodate the increased flow, and the bundles of tiny capillaries threading through the upper layers of skin are put into operation. The body's blood is circulated closer to the skin's surface, and excess heat drains off into the cooler atmosphere. At the same time, water diffuses through the skin as perspiration. The skin handles about 90 percent of the body's heat dissipating function.

Sweating, by itself, does nothing to cool the body, unless the water is removed by evaporation -- and high relative humidity retards evaporation. (The body can tolerate fairly high heat conditions (110-130oF.) if the humidity is low. You heard it said about Arizona and their extreme hot summers—“but, it’ a dry heat). The evaporation process itself works this way: the heat energy required to evaporate the sweat is extracted from the body, thereby cooling it. Under conditions of high temperature (above 90 degrees) and high relative humidity, the body is doing everything it can to maintain 98.6 degrees inside. The heart is pumping a torrent of blood through dilated circulatory vessels; the sweat glands are pouring liquid -- including essential dissolved chemicals, like sodium and chloride -- onto the surface of the skin.

Conditions that can induce heat-related illnesses include stagnant atmospheric conditions and poor air quality. Consequently, people living in urban areas may be at greater risk from the effects of a prolonged heat-wave than those living in rural areas. Also, asphalt and concrete store heat longer and gradually release heat at night, which can produce higher nighttime temperatures known as the "urban heat island effect."

Heat-Wave/Extreme Heat Terminology

The following table is the Heat Index defined by NOAA

Prolonged period of excessive heat, often combined with excessive humidity.

Heat Index
A number in degrees Fahrenheit (F) that tells how hot it feels when relative humidity is added to the air temperature. Exposure to full sunshine can increase the heat index by 15 degrees.

Heat Cramps
Muscular pains and spasms due to heavy exertion. Although heat cramps are the least severe, they are often the first signal that the body is having trouble with the heat.

Heat Exhaustion
Typically occurs when people exercise heavily or work in a hot, humid place where body fluids are lost through heavy sweating. Blood flow to the skin increases, causing blood flow to decrease to the vital organs. This results in a form of mild shock. If not treated, the victim’s condition will worsen. Body temperature will keep rising and the victim may suffer heat stroke.

Heat Stroke
A life-threatening condition. The victim’s temperature control system, which produces sweating to cool the body, stops working. The body temperature can rise so high that brain damage and death may result if the body is not cooled quickly.

Sun Stroke
Another term for heat stroke.

Feasibility of Heat-Wave Occurrence for Your Location

Extreme heat or heat-wave conditions can just about occur anywhere in the continental U.S.

Planning to Survive Heat-Wave Disasters

To prepare for extreme heat, you should:

  • If air conditioning is not already part of the residence or office, install portable window air conditioners snugly; insulate if necessary.

  • (Evaporative coolers fail to cool when humidity is high such as during the “Monsoon” seasons of the southern states).

  • Check air-conditioning ducts for proper insulation.

  • Install temporary window reflectors (for use between windows and drapes), such as aluminum foil-covered cardboard, to reflect heat back outside.

  • Weather-strip doors and sills to keep cool air in and hot air out.

  • Cover windows that receive morning or afternoon sun with drapes, shades, awnings, or louvers. (Outdoor awnings or louvers can reduce the heat that enters a home by up to 80 percent.)

  • Keep storm windows up all year.

  • New homes or replacement windows should be double pane.

  • Reflective coatings on windows or reflective screens are another level of heat reflection.

Actions to Take to Survive Heat-Wave Disasters from Occurring

What you should do if the weather is extremely hot.

  • Stay indoors as much as possible and limit exposure to the sun.

  • Stay on the lowest floor out of the sunshine if air conditioning is not available.

  • Consider spending the warmest part of the day in public buildings such as libraries, schools, movie theaters, shopping malls, and other community facilities. Circulating air can cool the body by increasing the perspiration rate of evaporation.

  • Eat well-balanced, light, and regular meals. Avoid using salt tablets unless directed to do so by a physician. Gatorade would help keep the electrolytes in the body satisfactory.

  • Drink plenty of water but don’t over indulge. Too much water could dilute the electrolytes in the body causing a different set of problems. (In the Southwest desert climate, rescued people often drink too much water afraid of dehydration and end up with a condition called hyper-hydration known as water intoxication or poisoning. See Historical Notes section for a detail definition and understanding.

  • Persons who have epilepsy or heart, kidney, or liver disease; are on fluid-restricted diets; or have a problem with fluid retention should consult a doctor before increasing liquid intake.

  • Limit intake of alcoholic beverages since these types of drinks dehydrate.

  • Dress in loose-fitting, lightweight, and light-colored clothes that cover as much skin as possible. Cotton fabrics are the coolest.

  • Protect face and head by wearing a wide-brimmed hat.

  • Check on family, friends, and neighbors who do not have air conditioning and who spend much of their time alone.

  • Never leave children or pets alone in closed vehicles.

  • Avoid strenuous work during the warmest part of the day. Use a buddy system when working in extreme heat, and take frequent breaks.

  • People in extreme heat environments start to work early and quit by noon. Those that continue working take their meals outside in the shade to stay acclimated to the temperature.

  • Try not to go back and forth numerous times between an air conditioned area and the outside. It is hard on the body.

  • If you must go shopping, try to do this as early in the day as possible or after the sun is down.

Additional Information To Prepare to Survive Heat-Wave Disasters

An emergency water shortage can be caused by prolonged drought, poor water supply management, or contamination of a surface water supply source or aquifer.

Drought can affect vast territorial regions and large population numbers. Drought also creates environmental conditions that increase the risk of other hazards such as fire, flash flood, and possible landslides and debris flow. See the post on Draughts.

Conserving water means more water available for critical needs for everyone. See the post on Draughts detailed suggestions for conserving water both indoors and outdoors. Make these practices a part of your daily life and help preserve this essential resource.

Actions to Take After Surviving Heat-Wave Disasters

Recovering from a disaster is usually a gradual process. Safety is a primary issue, as are mental and physical well-being. If assistance is available, knowing how to access it makes the process faster and less stressful. This section offers some general advice on steps to take after disaster strikes in order to begin getting your home, your community, and your life back to normal.

First Aid for Heat-Induced Illnesses

Extreme heat brings with it the possibility of heat-induced illnesses. The following table lists these illnesses, their symptoms, and the first aid treatment.





Skin redness and pain, possible swelling, blisters, fever, headaches.


  • Take a shower using soap to remove oils that may block pores, preventing the body from cooling naturally.

  • Apply dry, sterile dressings to any blisters, and get medical attention.



Heat Cramps


Painful spasms, usually in leg and abdominal muscles; heavy sweating.


  • Get the victim to a cooler location.

  • Lightly stretch and gently massage affected muscles to relieve spasms.

  • Give sips of up to a half glass of cool water every 15 minutes. (Do not give liquids with caffeine or alcohol.)

  • Discontinue liquids, if victim is nauseated.



Heat Exhaustion


Heavy sweating but skin may be cool, pale, or flushed. Weak pulse. Normal body temperature is possible, but temperature will likely rise. Fainting or dizziness, nausea, vomiting, exhaustion, and headaches are possible.


  • Get victim to lie down in a cool place.

  • Loosen or remove clothing.

  • Apply cool, wet clothes.

  • Fan or move victim to air-conditioned place.

  • Give sips of water if victim is conscious.

  • Be sure water is consumed slowly.

  • Give half glass of cool water every 15 minutes.

  • Discontinue water if victim is nauseated.

  • Seek immediate medical attention if vomiting occurs.



Heat Stroke ( a severe medical emergency)


High body temperature (105+); hot, red, dry skin; rapid, weak pulse; and rapid shallow breathing. Victim will probably not sweat unless victim was sweating from recent strenuous activity. Possible unconsciousness.


  • Call 9-1-1 or emergency medical services, or get the victim to a hospital immediately.

  • Delay can be fatal.

  • Move victim to a cooler environment.

  • Removing clothing

  • Try a cool bath, sponging, or wet sheet to reduce body temperature.

  • Watch for breathing problems.

  • Use extreme caution.

  • Use fans and air conditioners.





Caused by the excessive consumption of water which dilutes the body’s electrolyte balance. Drinking water in excess of 1.5--3 liters per day depending upon body mass can cause water intoxication.


Mild intoxication may remain asymptomatic and require only fluid restriction. In more severe cases, treatment consists of:

  • Diuretics to increase urination, which are most effective for excess blood volume.

Additional Resources for Surviving Heat-Wave Disasters

  • National Disaster Education Coalition consisting of:


Historical Notes Regarding Surviving Heat-Wave Disasters

Water intoxication (also known as hyper-hydration or water poisoning) is a potentially fatal disturbance in brain functions that results when the normal balance of electrolytes in the body is pushed outside of safe limits by over-consumption of water. Normal, healthy (physically, nutritionally and mentally) individuals have little reason to worry about accidentally consuming too much water. Nearly all deaths related to water intoxication in normal individuals have resulted either from water drinking contests, in which individuals attempt to consume high amounts of water, or long bouts of intensive exercise during which electrolytes are not properly replenished, yet excessive amounts of fluid are still consumed.

Water can be considered a poison when super-concentrated just like any other substance. The recommendation from the medical field is to drink about 1.5-3 liters per day depending upon body mass. Water intoxication would only occur at levels far higher than that. Most people drink too little water. Doctors who have analyzed recommendations based upon water intoxication have noted that water is so important to health that if people reduce their intake of water due to fear of water intoxication it could result indirectly in far more deaths than water intoxication itself.

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