Did You Notice? It's Hot. Here's What You Need To Know

This article is more than 9 years old.

In case you hadn’t noticed: It’s hot out there.

Until midday tomorrow, when a storm is expected to blow through bringing cooler air, it’s a good idea to stay somewhere with air conditioning and skip that run or garden overhaul you’ve been planning.

Weather like this is particularly dangerous for people who have lung conditions, are over 65, or young enough to think it’s a good idea to be outside in weather like this.

High humidity means that a key cooling mechanism for your body – sweating – won’t work as well. Normally, sweat evaporates, cooling you off. But when there’s so much moisture in the air that it can’t hold any more, that evaporation can’t occur.

Sometimes people compensate by drinking too much water or taking salt pills to allow themselves to continue their activity levels, despite the weather. Dr. Elliot Israel, professor of medicine at Brigham & Women's Hospital and Harvard Medical School, says that’s a bad idea because it can throw off the electrolyte imbalance and cause even more serious health problems.

Older people are also vulnerable because our body’s ability to cool itself becomes less efficient with age, Israel said. It’s particularly important for older people to avoid overheating, because they can often miss the danger signs, which include dizziness, nausea and headaches, he said.

Anyone with a lung condition like asthma or COPD is also at increased risk, because humid air can trigger bronchial spasms – twitching in the lung that limit breathing.

Bottom line: “Curtail activities outside in terms of strenuous continued exertion,” Israel says. “Try to keep yourself wet and hydrated sensibly. If you’re starting to get headache you need to really stop and get into a cool environment.”

Note: This post has been corrected to reflect that Dr. Israel works at Brigham & Women's Hospital.

This program aired on July 17, 2012. The audio for this program is not available.

Rachel Zimmerman Twitter Health Reporter
Rachel Zimmerman previously reported on health and the intersection of health and business for Bostonomix.