Not everyone experiences heat the same way, and studies show aggression, violence and road rage increase on hotter days

Recently, my husband and I embarked on what should have been a pleasant spring errand: a stroll to the local farmer’s market. But a passing heatwave had made it unseasonably hot outside. I cut him off on the sidewalk and he snapped at me, so I snapped at him for snapping at me. We spent the rest of the excursion in sweaty, stony silence. When we were almost home, he said, miserably: “I’m sorry! It’s just so hot.”

Our grouchiness was not simply a weakness of spirit. “Heat doesn’t just affect your body,” said Dr Susan Albers, clinical psychologist at the Cleveland Clinic. “It affects your mood too.”