Summer is upon us and things are heating up, literally. That’s worrisome given the effect that heat has on human health, both on the body and the mind.

The first major heat wave of the season scorched the western United States in recent weeks, with temperatures climbing to 114 degrees Fahrenheit in Las Vegas, and to a record-breaking 118 degrees in Phoenix.

The Pacific Northwest shattered previously recorded temperature highs, with many regions trapped under what experts called a blistering “heat dome.” In Boston, while a heat emergency was in effect, the city tied its record highs—which had stood since 1933—on June 28 and 29.

These hot days are not isolated events, and they are only going to get more common: the first comprehensive worldwide assessment of heat waves, a report released last summer, uncovered that in nearly every part of the world, heat waves have been increasing in frequency and duration since the 1950s.

Gregory Wellenius, professor of environmental health and director of the Program on Climate and Health at Boston University researches the human health impacts of a rapidly changing climate. His team aims to ensure that our communities are as resilient, sustainable, and healthy as possible, studying how climate change mitigation and adaptation policies can benefit human health.

Here, he answers some questions about how heat exposure impacts physical and mental health, policies that can ensure equitable access to “cooling centers,” and tips for staying safe when temperatures reach dangerous highs: