A heat wave is a prolonged period of excessively hot weather, which may be accompanied by high humidity. Extreme heat is defined as temperatures that hover 10 ° F or more above the average high temperature for the region and last for prolonged periods of time.
Under normal conditions, the body’s internal thermostat produces perspiration that evaporates and cools the body. In abnormal heat and high humidity, however, evaporation is slowed and the body must work extra hard to maintain its normal temperature. The elderly, the very young, and those who are disabled are at risk from extreme heat. Also, because men sweat more than women, they are more likely to have difficulty with extreme heat as a result of dehydration.
Studies indicate that excessive heat that continues for periods longer than 2 days causes a significant rise in heat-related illnesses. Spending several hours each day in air conditioning, however, can reduce the risk of heat-related illness.
People living in urban areas may be at greater risk from the effects of a prolonged heat wave than people living in rural regions. Stagnant atmospheric conditions can trap pollutants in urban areas, and asphalt and concrete stay warm longer. This phenomenon is known as the “urban heat island effect.”
During a heat wave, you should:
Seek air conditioning. If the home does not have air conditioning, persons should seek areas that do. Schools, libraries, shopping malls, community centers, and many other public places offer good refuges during extreme heat.
Avoid strenuous activities during the hottest period of the day. Heat-related illnesses can strike quickly, especially for those who perform strenuous work during the heat of the day.
Wear lightweight, light-colored clothing. Light colors reflect the sun’s rays better than dark colors, which absorb the heat. Protect the face and head by wearing a wide-brimmed hat.
Check on family members and neighbors who do not have air conditioning or who have medical problems that make them particularly susceptible to heat-related illnesses.
Drink plenty of fluids. Dehydration can occur quickly and can be unnoticed or mistaken for other illnesses. Increasing fluid intake, even if not thirsty, can reduce the risk of dehydration.
Remember, however, that persons who are on fluid-restrictive diets (e.g., those with kidney disease) should consult their doctors before increasing fluid intake.
Take frequent breaks. To protect against excessive heat in the home. Taking frequent breaks and seeking shade allows the body to cool down.