Heat kills by taxing the human body beyond its abilities. In a normal year, about 175 Americans succumb to the demands of summer heat. In the 40-year period from 1936 through 1975, nearly 20,000 people were killed in the
Click HERE for more information about Heat Waves and ways to protect you and your family.
How Heat Affects the Human Body
When blood is heated above 98.6 degrees, human bodies dissipate the heat by varying the rate and depth of blood circulation, by losing water through the skin and sweat glands, and by panting. 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.
Understanding the Heat Index
Based on the latest research findings, the NWS has devised the “Heat Index” (HI). The HI, given in degrees Fahrenheit, is an accurate measure of how hot it really feels when relative humidity (RH) is added to the actual air temperature.
To find the HI, look at the Heat Index Chart. As an example, if the air temperature is 95°F and the RH is 55%, the HI-or how hot it really feels-is 110°F. This is at the intersection of the 95° row and the 55% column.
Click on image for larger version.
IMPORTANT: Since HI values were devised for shady, light wind conditions, EXPOSURE TO FULL SUNSHINE CAN INCREASE HI VALUES BY UP TO 15°F. Also, STRONG WINDS, PARTICULARLY WITH VERY HOT, DRY AIR, CAN BE EXTREMELY HAZARDOUS.
Heat Wave Safety Tips
Slow down. Strenuous activities should be reduced, eliminated, or rescheduled to the coolest time of the day. Individuals at risk should stay in the coolest available place, not necessarily indoors.
Dress for summer. Lightweight light-colored clothing reflects heat and sunlight and helps your body maintain normal temperatures.
Put less fuel on your inner fires. Foods (like proteins) that increase metabolic heat production also increase water loss.
Drink plenty of water or other non-alcohol fluids. Your body needs water to keep cool. Drink plenty of fluids even if you don’t feel thirsty. Persons who (1) have epilepsy or heart, kidney, or liver disease, (2) are on fluid restrictive diets or (3) have a problem with fluid retention should consult a physician before increasing their consumption of fluids. Do not drink alcoholic beverages.
Do not take salt tablets unless specified by a physician.
Spend more time in air-conditioned places. Air conditioning in homes and other buildings markedly reduces danger from the heat. Spending some time each day (during hot weather) in an air conditioned environment affords some protection.
Don’t get too much sun. Sunburn makes the job of heat dissipation more difficult.
HEAT CRAMPS: Painful spasms usually in muscles of legs and abdomen are possible. Heavy sweating. First Aid: Firm pressure on cramping muscles or gentle massage to relieve spasm. Give sips of water. If nausea occurs, discontinue use.
HEAT EXHAUSTION: Heavy sweating, weakness, skin cold, pale and clammy. Pulse thready. Normal temperature possible. Fainting and vomiting. First Aid: Get victim out of sun. Lie down and loosen clothing. Apply cool, wet cloths. Fan or move victim to air conditioned room. Sips of water. If nausea occurs, discontinue use. If vomiting continues, seek immediate medical attention.HEAT STROKE: High body temperature (106° F. or higher). Hot dry skin. Rapid and strong pulse. Possible unconsciousness. First Aid: HEAT STROKE IS A SEVERE MEDICAL EMERGENCY. SUMMON EMERGENCY MEDICAL ASSISTANCE OR GET THE VICTIM TO A HOSPITAL IMMEDIATELY. DELAY CAN BE FATAL. Move the victim to a cooler environment Reduce body temperature with cold bath or sponging. Remove clothing. Use fans and air conditioners. If temperature rises again, repeat process. Do not give fluids. Persons on salt restrictive diets should consult a physician before increasing their salt intake.