If it’s summer and you’re in Arkansas, you know it’s coming – a fry-an-egg-on-the-pavement heat wave. Even if it’s not an official heat wave, we have many more weeks of hot, humid weather before fall. Here are the summer’s best survival tips.

Do you know the symptoms of heat exhaustion or heat stroke? Learn how to treat heat-related illness and how to protect yourself during summer.

Heat can be a killer if you don’t take precautions. Heat waves kill more people in the United States than all other natural disasters combined. The Center for Climatic Research says an average of 1,500 people die annually because of the heat.

What is a heat wave?

A heat wave is a prolonged period of excessively hot weather, usually with high humidity, when compared to the area’s usual weather and normal temperatures for the season. It is also defined as a period of more than five consecutive days with the temperature at least 9 degrees F. higher than the average maximum temperature.

The “heat index” is what the temperature feels like to the human body when the humidity is high. It combines air temperature and relative humidity (moisture in the air).

When we get hot, our bodies cool down by sweating. As the sweat evaporates, the body’s temperature cools. However, on a humid day when the air is full of moisture, sweat cannot evaporate and the body stays hot. The opposite is true then humidity is low, or you’re in a dry climate, and the body’s ability to cool itself by sweating increases.

When is the heat index dangerous?

A heat advisory means a period of hot temperatures is expected and the heat index is likely to create a situation where heat-related illness is possible. The danger from heat is also higher when air pollution is high.

The usual progression of heat-related illness, according to the Centers for Disease Control and Prevention (CDC) is:

  • Heat exhaustion causes heavy sweating, nausea or vomiting, fainting, a racing pulse and clammy skin. The person may also stagger, be confused or combative. Muscle cramps are often an early sign. To reverse it, stop activity, move to a cool location and apply wet cool washcloths to the body. Heat exhaustion requires immediate medical treatment and rapid cooling. If you cannot reverse it, it quickly advances to heat stroke.
  • Heat stroke occurs when the body’s core temperature is higher than 104 degrees (give or take a couple of degrees, depending on the individual’s heat tolerance). Sweating stops, pulse is rapid, and the skin is flushed and dry. The person becomes delirious and may faint. About 10 percent of heat stroke victims die. If they survive, they often have brain damage.

Heart attacks and strokes are more common when there’s a heat wave. The heart has to work harder and faster. Even a healthy person can die of heart attack or stroke if they try to do too much outside on a hot, humid day.

The National Weather Service offers this chart to help you decide if it’s safe to be outside. Remember, these temperatures are for shady locations. If you are in direct sunlight, the heat index can be 15 degrees hotter.

Danger Level         Heat Index                      Effect on the body                       

Caution                  80-90 degrees            Fatigue possible with long exposure or                                                                                                                   physical activity outdoors

Extreme caution    90-103 degrees           Cramps, heat exhaustion, heat stroke occur                                                                                                          with long exposure or physical activity

Danger                 103-124 degrees         Heat exhaustion likely, heat stroke possible with                                                                                                   long exposure or activity outdoors

Extreme danger       125+ degrees           Heat stroke highly likely

How do heat waves kill so quickly?

When the body cannot cool itself by sweating or the person cannot get a break –even for a few hours of air conditioning – the body’s systems break down. Called hyperthermia, it’s the opposite of hypothermia that can happen during winter. Hyperthermia means the body’s temperature is dangerously high. It is caused by failure of the body’s heat-regulating process.

Hyperthermia causes the body to try to cool the blood by dilating blood vessels in the skin and constricting blood vessels in the stomach. Less blood to the gut lets toxins leak into the blood. Cells begin to die, triggering a massive inflammatory response that damages the body’s tissues, organs and the kidneys start to fail. Proteins in the spleen start to clump and essentially “cook.” Toxins also enter the brain causing strokes and swelling.

This process can happen very quickly; the person may not be aware of the danger. The majority of heat wave deaths occur in older persons and the mentally ill. Older people have more trouble regulating their temperature, and they are less likely to know they are too hot. Additionally, some medicines commonly used by older people can make temperature regulation worse. A third factor is they tend to be more socially isolated than younger people. Social isolation is the greatest risk factor for dying during a heat wave.

Heat survival tips

Be sure you and your family follow these nine safety tips this summer:

  1. Start prevention early and stay hydrated by drinking half a gallon of water per day if you are indoors. Add to this, 34 to 68 additional ounces of water for every hour of outdoor time, depending on how active you are. Drink before you feel thirsty. If you feel thirsty, you’re already dehydrated.
  2. Avoid alcoholic or caffeine drinks because they can cause the body to lose more fluids through urine.
  3. Wear lightweight, light-colored clothing, made of natural fabric or special fabrics designed to wick-away sweat.
  4. Use a sun hat or umbrella outdoors.
  5. Eat smaller, more frequent meals.
  6. Stay indoors as much as possible. If you do not have air conditioning, try to go to a place that is air conditioned for part of the day – library, shopping mall, movie theatre or museum, or visit friends who have air conditioning. The most crucial hours are generally from 1 to 6 p.m.
  7. Avoid strenuous activity, especially during the hottest part of the day. If you must be outside, take regular breaks.
  8. Check daily or twice daily during a heat wave on older people, sick or obese people and people who are socially isolated. If you are unable to contact them, go to their location or call 911 with their address. People with heart, lung or kidney disease; ill with a fever; or have high blood pressure, a chronic condition or poor circulation are especially vulnerable during a heat wave. Taking medications such as diuretics, sedatives, tranquilizers, and some heart and blood pressure drugs can also make a person more vulnerable to heat illness. The third day of a heat wave is critical for the human body. Those who have endured extreme heat often can no longer cope after the third day, especially if temperatures remain high at night.
  9. If you suspect someone is suffering from a heat-related problem:
  • Get him out of the heat and into a shady area or air-conditioning.
  • Urge him to lie down and loosen clothing so you can apply cool, wet washcloths directly to bare skin. For quickest blood cooling, apply to the neck, wrists, armpits and groin areas.
  • Help him to bathe or sponge off with cool water.
  • If he is conscious and can swallow safely, offer cool water, fruit or vegetable juices. No alcohol or caffeine.
  • If at any time he becomes unresponsive, confused or combative, or has trouble breathing, call 911 immediately. This is a medical emergency!