Having a Heat Wave!
A heat wave is a long period of very high heat and humidity. The National Weather Service has come up with a heat index (HI) to warn the public about such conditions. The HI, given in degrees Fahrenheit, is a measure of how hot it really feels when the actual air temperature is combined with the relative humidity (which is a measure of the amount of moisture in the air compared to the greatest amount of moisture the air could hold at the same temperature). For example, if the air temperature is 95 degrees Fahrenheit and the relative humidity is 55 percent, the HI, or how hot it really feels, is 110 degrees F. The National Weather Service issues alerts when the HI is expected to be greater than 105 to 110 degrees Fahrenheit for at least two days in a row.
What Are Heat-Related Injuries?
There three types of heat-related injuries:
- Heat cramps. These are painful muscle cramps, usually in the stomach, arms, or legs, that may occur during heavy activity. Heat cramps are the least serious type of heat-related injury. It can be dangerous to ignore them, however, since they are an early warning sign that the body is having trouble with heat.
- Heat exhaustion. This is the body's response to losing too much water and salt in sweat. It often occurs in people who exercise heavily or work in a hot, humid place, which makes them sweat a lot. Elderly people and those with high blood pressure are also prone to heat exhaustion. As the body overheats, blood flow to the skin increases, which decreases blood flow to other organs and causes weakness, confusion, and can cause collapse. If heat exhaustion is not treated, the person may suffer heat stroke.
- Heat stroke. This is the most serious type of heat-related injury. Heat stroke, also known as sun stroke, occurs when the body becomes unable to cool itself down. The body's temperature may rise to 106 degrees Fahrenheit or higher within minutes. If heat stroke is not treated quickly, it can lead to brain damage or death.
How Can Heat Injury Be Prevented?
To prevent heat-related injuries, keep cool and use common sense. The following tips may help on hot, summer days:
- It is important to consume plenty of fluids, regardless of thirst. During heavy exercise in hot weather, it is important to drink at least two to four glasses of cool fluid each hour. Water is always a good drink choice. Very cold drinks can cause stomach cramps. Avoiding drinks containing caffeine, such as iced teas and colas, is important because they just cause the body to lose more fluid. Salt tablets should be avoided.
- Slowing down the pace is important also. It is important to cut back on heavy exercise, or to move it to the coolest time of day, usually very early in the morning.
- Staying indoors if possible also can help. The best way to beat the heat is to stay in an air-conditioned room. An electric fan can make things more comfortable, too, but a fan alone may not be enough during a severe heat wave. If it is very hot at home, spending a few hours at an air-conditioned mall or public library can help.
- Lightweight, loose-fitting clothing also helps. Light-colored fabrics are the best, because they reflect away some of the sun's energy.
- It is helpful to eat smaller, more frequent meals, to avoid generating the extra body heat associated with digesting large meals.
Who Is At Risk?
Several things affect the body's ability to cool itself during very hot weather. One of the main ways the body cools itself is by sweating. The evaporation of sweat from the skin cools the body. When humidity (the amount of moisture in the air) is high, the sweat does not evaporate from the skin. Other things that can limit the body's ability to control its temperature include old or very young age, being overweight, fever, heart disease, sunburn, alcohol or drug use, and dehydration (dee-hy-DRAY-shun), which is excessive loss of water from the body due to illness or not drinking enough liquids.
Some people have a high risk of heat-related injuries:
- Babies and children under age four. Babies and young children are very sensitive to the effects of high temperatures. They become dehydrated very quickly because of their small size. They are also unable to help themselves if they start to get overheated.
- People over age 65. An older person's body may not control its own temperature as well as a younger person's. Older people are also less likely to notice and respond to changes in temperature.
- People who are ill or taking certain medicines. Any illness or medicine that leads to dehydration raises the risk of heat-related injuries.