When sustained heat waves hit a region, heat related injury and health ramifications can be serious, including sunstroke and even major organ damage due to heat.According to the Center for Disease Control, extreme heat is blamed for 700 deaths each year in the U.S. They tend to happen in small epidemics when we are confronted with heat waves as we are experiencing this time of year. Some experts predict this may be more commonplace due to overall global climate changes.
Heat exhaustion is a relatively common reaction to severe heat and includes symptoms such as dizziness, headache and fainting. If left untreated, it can progress to heat stroke. When severe, it requires medical attention. The severe form manifests when someone can no longer cool their body after profuse sweating, leading to dry skin, a body temperature above 103 degrees Fahrenheit, heat rash, muscle cramps, confusion and sometimes unconsciousness. Profoundly dangerous effects to the central nervous system and circulation can happen quickly when warning signs are ignored.
Humans cope with heat by expelling some heat through their breath and perspiring. The evaporation of moisture off the surface of our skin dissipates the internal heat. High humidity makes this very difficult because the cooling effect is seriously impaired. The published Heat Index estimates how it feels and how much the humidity can increase the effect of a given temperature, which can be 15 degrees or more when humidity is high.
Urban areas are known to be “islands of heat.” The vast amount of concrete and asphalt absorbs and radiates the heat to a great extent. The increased density of people and heat producing machinery put urban dwellers at much greater risk than their rural counterparts. This is particularly dangerous when a heat wave lasts more than two days. The nights do not cool down due to the stored heat and people do not get a break from the prolonged heat. More urban heat related deaths occur at night.
Who is affected most?
Elderly, the very young, people with chronic illness are most vulnerable. Some medications may make people more sensitive to the heat (diuretics, beta blockers, mental health meds) Discuss your concerns with your physician to see if any special precautions are recommended. But even healthy people who have to work or exercise in extreme heat are subject to dangerous effects.
The single most helpful thing you can do in extreme heat is spend several hours a day in air conditioning. If you do not have air conditioning, plan to spend time with someone who does. Many public buildings are available that have climate control such as libraries, schools, shopping malls, coffee shops. Fans do help with the evaporation/cooling process. They can also be more detrimental when simply blowing more hot air around. It can be comparable to a convection oven, magnifying the bad effects of the heat. During periods of extreme heat stay indoors and avoid direct sun. Slow down and avoid strenuous activities.
Even healthy, well-conditioned athletes are vulnerable to dangerous effects of heat.
What can you do?
If you have to work outside you need a plan — wear loose fitting, lightweight, light colored clothing. Use a wide brimmed hat to protect the head and face. Drink plenty of fluids. Water is the best. Alcohol and caffeinated beverages should be avoided as they can make things worse. Eat light food in smaller amounts but more often. Take frequent breaks to get out of the direct sun and catch up on fluids. Water consumption is top of the list. Two liters a day is a good start for a normal healthy person. In extreme heat the need goes up dramatically. Some sports drinks without caffeine can be suitable but should not be the sole source of fluid replacement.
With only a small bit of planning and common sense you can survive the heat wave comfortably and safely.
Dr. Bruce Kaler