Selfishness in the summertime

Q: Sometimes I feel like people get more testy in hot weather. Is there anything to this? — Charlene A., Springfield, Ill.

A: Summertime out-of-sorts is a real phenomenon. And a recent study confirms that people are less likely to feel kindly toward others when they’re hot.

Researchers did three different experiments, and all led to the same conclusion.

■ They found retail employees in an uncomfortably warm store were 50 per cent less likely to do helpful things for customers compared with workers working in a comfortable temperature.

■ A second experiment revealed that just the thought of being hot made people less likely to want to help others. The researchers paid people to take an online survey, but first they had half of them imagine a time they were uncomfortably hot. After the paid survey ended, they asked people to take an extra survey for no pay. A full 76 per cent of people who had not imagined being hot were willing to take the extra survey, but only 34 per cent of those who’d thought about being overheated were willing.

■ In their last experiment, the authors found 95 per cent of college students in a cool room agreed to fill out a survey to benefit a local nonprofit, compared to 65 per cent of those in a room heated to 80 degrees.

The researchers think that heat makes people more tired. We speculate that heat triggers an inflammatory response that boosts stress hormones, aggravates residual pains or ailments and amps up mood-altering hormones.

Be mindful of your mood and then be generous to others — they’re hot, too, and could use a cooling act of kindness.