High Temperatures, Humidity Don't Mix

With summer on the way, Nebraskans will have to be alert to the combination of high heat and high humidity.

"Temperatures of 90-plus degrees and humidity levels of 35 percent or more put us in the danger zone for heat-related illness," said Dr. Richard Raymond, the System's former chief medical officer.

People suffer health-related illness when the body's temperature control system is overloaded. The body normally cools itself by sweating. When the humidity is high, sweat will not evaporate as quickly, preventing the body from releasing heat quickly. The result can be heat stroke or heat exhaustion.

The risk for heat-related illness and death is higher for infants and the elderly, whose internal thermostats do not regulate body temperature well.

Others who are at increased risk are the obese, the chronically ill (which includes those with heart disease, high blood pressure and asthma), and people who take certain medications, such as antidepressants and tranquilizers, that interfere with the body's temperature regulation.

Heat-related illness and death are readily preventable, Dr. Raymond said.

Here are some tips for hot times ahead:

• Spend as much time as possible in air-conditioned places;
• Drink plenty of water--avoid alcohol and drinks with caffeine;
• Wear loose, light-colored clothing;
• Eat light meals;
• If outdoor activity is unavoidable, slow your pace and take frequent rest breaks to cool off.
• Protect your skin by using a sunscreen lotion with a protective factor of 15 or greater and wearing a wide-brimmed hat, long-sleeved shirt and pants. Sunburn interferes with the body's job of heat dissipation, and too much sun exposure is a risk factor for skin cancer.

Being in an air-conditioned place for a few hours each day will reduce the risk of heat-related illness. Fans can be a source of relief, but the higher the humidity, the less cooling relief they provide. Air movement at high levels of humidity can increase heat stress.

Heatstroke, the most serious heat-related illness, is a medical emergency characterized by a body temperature of 105 degrees F (Fahrenheit) or greater. Symptoms include hot dry skin, rapid heartbeat, shallow breathing, disorientation, delirium, and coma. An individual suffering from heat stroke should be moved into the shade or into an air-conditioned location and emergency medical assistance should be summoned.

Heat exhaustion is a milder form of heat-related illness that can develop following exposure for several days to high temperatures. It is characterized by rapid heartbeat, cold clammy skin, nausea, dizziness, weakness, and fatigue. An individual suffering from heat exhaustion should be moved into the shade or into an air-conditioned location immediately. If the individual's temperature exceeds 102 degrees F, seek emergency medical assistance.

NOTE: Below is a heat stress index. The numbers in the shaded area indicate the danger zone for heat stroke and heat exhaustion.