By Brad Salzmann, PA-C
Even short periods of high temperature, humidity, or exertion can cause serious health problems. Heat-related illness and deaths are preventable, yet many people suffer serious health illness or death every year.
The Centers for Disease Control and Prevention reported an average of 618 heat-related deaths per year in the United States from 1999-2010. Extreme heat is defined as temperatures that are substantially hotter and/or more humid than are typical for that location at that time of year.
HOW MUCH HEAT IS TOO MUCH?
There is no specific temperature or humidity level that must be obtained for heat-related illness or death to occur. The National Institute for Occupational Safety and Health, for example, reported a healthy 30-year-old landscaper died of heat stroke on a day that never went higher than 81 degrees. Heat-related illness and death rather occurs when heat pushes the body beyond its ability to compensate. The human body cools itself by sweating; the sweat brings heat to the surface where it evaporates. High humidity reduces the ability of sweat to evaporate.
WHO IS AT MOST RISK?
Body heat is produced two ways: internal (metabolic) heat is generated by physical exertion, and environmental heat is from high air temperature; humidity; direct sun exposure; heavy clothing; and lack of water, rest, and cooling. Anybody can succumb to heat. However, the elderly; very young; people with handicaps who are unable to take care of themselves or communicate; those with mental illness, cardiovascular, lung or other chronic diseases are at increased risk. Outdoor workers in agriculture, construction, logging, and firefighting are at increased risk, as well as those involved in exertional exercise outdoors. Statistically, 68 percent of heat-related deaths are male. There are some studies that predict risks will increase with climate change.
Heat rash is a skin irritation caused by excessive sweating; it is most common in young children. Heat rash looks like a collection of pimples or small blisters, usually on the neck, chest, or in the groin and elbow creases. Treatment for heat rash is to provide a cooler, less humid environment; dusting powder may help.
Heat cramps are caused by excessive sweating, which depletes the body of salt and fluid. Heat cramps are muscle pains or spasms, usually in the abdomen, arms, and legs. Heat cramps can be serious for those with heart disease or who are on a low-salt diet, and medical attention should be obtained. Otherwise, stop all activity, sit quietly in a cool place, drink clear juice or a sports beverage, and rest for several hours after cramps subside. If cramps do not subside within an hour, seek medical attention.
Heat exhaustion is a body’s response to an excessive loss of fluid and salt. It can develop after several days of exposure and inadequate replacement of water and electrolytes. Symptoms of heat exhaustion include heavy sweating, paleness, muscle cramps, tiredness, weakness, dizziness, headache, nausea/vomiting, and fainting. Signs include cool, moist skin; rapid, shallow breathing; and a fast, weak pulse. The elderly and people with high blood pressure or who work or exercise in a hot environment are at higher risk. Treat heat exhaustion with cool (non-alcoholic) fluids, rest, cool shower/bath, air conditioning, and light-weight clothing.
Heat stroke is a medical emergency; call 911 immediately. The body is unable to regulate its temperature, which can rise rapidly. The sweating mechanism fails and fatal temperatures can rise to 106 degrees or higher within minutes. Heat stroke can present with an extremely high body temperature; red, hot, dry skin (no sweating); rapid, strong pulse; throbbing headache; dizziness; nausea; confusion; unconsciousness; or seizures. Immediate cooling is necessary! Begin cool water immersion, shower, spray, sponging, wrapped in cool wet sheets, and vigorous fanning until emergency medical services are available. Do not give fluids by mouth.
Sunburn can cause first or second-degree burns. Ultraviolet radiation (sun exposure) damages the cells of the skin. Protect skin from excessive exposure by seeking shade, especially during the midday hours; wearing lightweight clothing, hats, sunglasses with UVA and UVB protection; frequent application of sunblock (SPF 15 or higher); and avoiding indoor tanning.
Skin cancer risk is increased with exposure to the sun. The three most common types are basal cell, squamous cell, and melanoma. Skin cancers can invade normal nearby tissue and sometimes spreads to other parts of the body. Prevention is the best treatment.
Air conditioning is the number one protective factor for heat-related illness and death. Increase fluid levels during hot weather. Don’t wait until you are thirsty; thirst is a late indicator of dehydration. Don’t drink fluids with alcohol or large amounts of sugar. If you are not urinating every two to three hours or the urine is dark, then you need to drink more. Acclimation occurs over the course of several weeks and actually causes a body to sweat more efficiently.
Minimizing exposure, staying well hydrated, frequent rests, protective clothing, and acclimation all reduce the risks of heat-related illness.
Brad Salzmann is an orthopedics physician assistant at Gifford. He also has a master’s degree in disaster medicine and management, and serves as part of a national Disaster Medical Assistance Team based in Worcester, Mass.