It’s possible to train your body to better handle high temperatures in just a few weeks.
Inside a small, sealed room, Olivia Leach swallowed a pill that would soon monitor her internal temperature. She then hopped on a stationary bike and prepared to sweat. Slowly, as she began to pedal, the room started to heat up at a rate of one degree every five minutes.
It felt “like a muggy, hot summer day where you’re just drenched in sweat,” said Ms. Leach, a doctoral student at Pennsylvania State University.
Ms. Leach works in the lab of W. Larry Kenney, a physiology and kinesiology professor at Penn State. The lab’s work is part of a growing body of research exploring how the body deals with heat, and how to help people acclimate to hotter weather.
Ms. Leach and other experts said that this research had become more urgent as more parts of the world faced an increasing number of dangerously hot days. In the United States alone, extreme heat caused at least 2,302 deaths in 2023, and some research suggests that number may be far higher.
Without the right preparation, pushing the body too hard in extreme heat can be deadly. Almost half of all heat-related deaths among workers occur on the first day on the job, and more than 70 percent occur within the first week, according to the Occupational Safety and Health Administration. Recognizing those risks, the Biden administration recently proposed new rules to protect people who work in the heat.
The proposal would entitle workers to so-called acclimatization plans, which would let new employees who aren’t used to high temperatures safely adjust to heat by gradually increasing their hours.