When the outside temperature rises above the normal core body temperature of 98.6°F (37°C), internal mechanisms for releasing heat kick in, including sweating, more blood pumped by the heart, and more blood flowing to the skin. Poor aerobic fitness; chronic cardiovascular, kidney, or respiratory conditions; and some medications can reduce a body’s ability to adapt to high temperatures and increase the risk of heat exhaustion and life-threatening heatstroke (in which the core body temperature reaches 105°F or 40.6°C). Other risk factors for heat illness identified in the report are confinement to bed, not leaving the home every day, having a psychiatric illness, and being unable to care for oneself.
The report’s authors looked at many sources of advice for preventing heat-related illness and found that many of the suggested precautions are supported by science but some are not. The best recommendations:
The report points out that some common suggestions are not as well supported. For example, using electric fans, while not dangerous, has not been found to be helpful, and moderate consumption of caffeinated drinks and low-alcohol content drinks such as beer, despite their diuretic effects, do not appear to increase the risk of heat-related problems.
Heatstroke can come on very quickly once the body has lost its ability to cope with heat, so pay attention to the signs of heat-related stress:
These are signs that you need to cool off, so take a rest from physical activity, drink a tall glass of water, and take a cool shower. If you or someone you are with experiences severe symptoms such as intense nausea, vomiting, or fainting, seek emergency medical care.