A heat wave is defined as a prolonged period of excessive heat.  Fortunately in Texas, we often have dry heat but not always.  Extreme heat and humidity can be a lethal combination.

Heat can kill by pushing the human body beyond its natural limits.  Extreme heat and humidity causes evaporation to slow and the body must work harder to stabilize at its normal temperature.  Most heat disorders happen because someone has been over-exposed to heat or has over-exercised based on age and physical condition.  Specifically at risk are older adults, young children, those who are ill and overweight people.

People in urban areas are at greater risk of harm from a prolonged heat wave than those living in rural areas.  This is due to pollution, stagnant air and other conditions in cities.  Additionally, asphalt and concrete store heat and can gradually release heat at night.  This is called the “urban heat effect,” and produces higher nighttime temperatures.

Most heat disorders occur because the victim has been overexposed to heat or has over-exercised for his or her age and physical condition. Older adults, young children, and those who are sick or overweight are more likely to succumb to extreme heat.

Conditions that can induce heat-related illnesses include stagnant atmospheric conditions and poor air quality. Consequently, people living in urban areas may be at greater risk from the effects of a prolonged heat wave than those living in rural areas. Also, asphalt and concrete store heat longer and gradually release heat at night, which can produce higher nighttime temperatures known as the “urban heat island effect.”

On a national basis, California, Nevada and Arizona hold the record high temperatures at 125-134!  Texas and several other states come in second at temperatures of 116-122.

The following are general terms that relate to effects from the heat:

Heat Wave - Prolonged period of excessive heat, often combined with excessive humidity.

Heat Index - A number in degrees Fahrenheit (F) that tells how hot it feels when relative humidity is added to the air temperature. Exposure to full sunshine can increase the heat index by 15 degrees.

Heat Cramps - Muscular pains and spasms due to heavy exertion. Although heat cramps are the least severe, they are often the first signal that the body is having trouble with the heat.

Heat Exhaustion – Often occurs from working or exercising in a hot, humid place where body fluids are lost through heavy sweating. Blood flow to the skin increases, causing blood flow to decrease to the vital organs. This results in a form of mild shock. If not treated, the victim’s condition will worsen. Body temperature will keep rising and the victim may suffer heat stroke.

Heat Stroke (also known as “sun stroke“) – A life-threatening condition. The victim’s temperature control system, which produces sweating to cool the body, stops working. The body temperature can rise so high that brain damage and death may result if the body is not cooled quickly.

When the weather becomes extremely hot and humid, here are some tips for ensuring you and your family are safe:

1. Stay indoors and limit sun exposure.
2. Stay on the lowest floor of a building if air conditioning isn’t available.
3. If you get cabin fever by staying at home, spend the warmest days in public buildings such as libraries, or movie theaters, shopping malls, etc.  Circulating air can cool the body by increasing perspiration rate of evaporation.
4. Eat light and regular meals.  Avoid salt tablets.
5. Drink plenty of water. Limit intake of alcoholic beverages.
6. Wear loose-fitting, lightweight and light-colored clothes that cover your skin as much as possible.
7. Protect your head with a hat.
8. Never leave children or pets alone in closed vehicles.
9. Avoid strenuous outdoor work during the warmest part of the day.
10. Always wear the highest possible level of sunscreen to avoid sunburn and ultimately, skin cancer.

If you must be outdoors during extreme heat, the following are tips on avoiding negative effects of the sun:

1. Drink 12 to 20 ounces of water 2 to 3 hours before beginning the sport.
2. Drink plenty of water often during physical activity – 8 to 12 ounces of water every 15 to 20 minutes of exercise.
3. Drink plenty of water after exercise to avoid heat exhaustion and heat stroke.
4. Know that medications can affect thermoregulation in hot weather, and cause you to become dehydrated.
5. Smaller children are at a greater risk of dehydration during hot, humid days and should drink 3 to 6 ounces of fluid every 15 to 20 minutes.
6. Certain sports drinks may be fine for replacing water, but according to the Texas A&M University’s College of Medicine, water is always the preferred choice.
7. Do not take salt tablets in the heat.
8. Avoid drinks with caffeine, which increases dehydration and muscle cramps.
9. Take frequent breaks.

Because avoiding serious heat problems is so important, I’ll  follow up this blog entry with more important safety tips soon.