Aug. 13, 2007 -- With much of the U.S. sweltering in a heat wave, two new studies show who may be most vulnerable to death from heatstroke or other heat-related illnesses.
Leading that list are older adults -- especially those who can't take care of themselves -- and people taking medications to treat their high blood pressure.
Those findings reinforce health advice to stay out of extreme heat, seek shelter in air-conditioned places, and check in on vulnerable relatives and neighbors.
Before you read the studies' details, take a moment to learn the symptoms of heatstroke and what to do about it.
Warning Signs of Heatstroke
Heatstroke is the most serious heat-related illness. Without emergency medical care, it can kill or leave people permanently disabled.
The CDC's web site states that the warning signs of heatstroke vary but may include the following:
- An extremely high body temperature (above 103 degrees Fahrenheit)
- Red, hot, and dry skin (no sweating)
- Rapid, strong pulse
- Throbbing headache
Heatstroke: What to Do
The CDC offers this advice about what to do if you see someone with heatstroke symptoms:
- Have someone call for immediate medical assistance while you begin cooling the person who has heatstroke symptoms.
- Get the person to a shady area.
- Cool the person rapidly, using whatever means you can. For example, immerse them in a tub of cool water, place them in a cool shower, spray them with cool water from a garden hose, or, if the humidity is low, wrap them in a cool, wet sheet and fan them vigorously.
- Get medial assistance as soon as possible. If emergency personnel are delayed, call the hospital emergency room for further instructions.
- Don't give the person suffering from heatstroke any fluids to drink.
The two new studies, published in the Archives of Internal Medicine, are based on previous heat waves in the U.S. and Europe.
One of the studies focuses on the French heat wave of August 2003, in which 14,800 people died of heat-related illnesses.
Laurent Argaud, MD, PhD, and colleagues reviewed the cases of 83 people treated for heatstroke at their hospital in Lyon, France, during the heat wave.
Most of those patients -- 84% -- were older than 70. Virtually all -- 96% -- had at least one other medical condition.
Patients were particularly likely to die of heatstroke if they lived in nursing homes; were taking high blood pressure medications for a long time; or arrived at the hospital in a coma, with heart failure, or who were not making any urine.
The Lyon hospital didn't have air conditioning. It's not clear if the patients' nursing homes were air conditioned.
Air conditioning can make a difference in preventing heatstroke, and Western countries "need to be more prepared for future heat waves," write Argaud and colleagues.
The other new report details risk factors for heat-related deaths, including heatstroke.
The researchers included Abderrezak Bouchama, MD, of Saudi Arabia's King Faisal Specialist Hospital and Researcher Center.
They pooled data from six studies of U.S. and European heat waves, including 1,065 people who died of heat-related illnesses and about 1,400 survivors of those heat waves.
People were most likely to die of heat-related illnesses if they were confined to bed, didn't leave home daily, and couldn't take care of themselves. Those with psychiatric, heart, or lung illnesses were also at increased risk of heat-related death.
Having an air-conditioned home, going to air-conditioned buildings, and participating in social activities reduced the odds of heat-related death, Bouchama's team reports.