Risks of Exercising in the Heat

Extreme heat waves are increasing in frequency, thanks in part to climate change. In addition to heatstroke, experts caution about other heightened risks that can occur when exercising in the heat, particularly for those with preexisting cardiovascular conditions. “Although we don’t yet fully understand the reasons, people with cardiovascular disease are at greater risk of hospitalizations and death during extreme heat events,” said senior study author Daniel Gagnon, PhD, researcher at the Montreal Heart Institute and School of Kinesiology and Exercise Science, University of Montreal, Quebec. “It is likely that heat exposure increases myocardial oxygen needs.”

Preventive strategies include paying attention to extreme heat warnings, identifying signs of heat stress, drinking adequate amounts of fluid and seeking air-conditioned environments. Alternatives to air conditioning include using an electric fan, wetting the skin and immersing the feet in tap water. More research is needed to identify safe environmental limits for outdoor exercising in the heat in individuals with heart disease.

The review is published in the Canadian Journal of Cardiology (2021; 37 [11], 1828–36).

See also: Making Outdoor Fitness Work