There’s a new threat from global warming. A new study shows that it may reduce male sperm counts. The study conducted at the University of East Anglia in the U.K. clearly showed that male fertility seems to decline as temperatures soar.

“Research has shown that heat shock can damage male production in warm blooded animals and past work has shown that this leads to infertility in mammals,” says lead author Kirs Sales, of the University of East Anglia. The study used beetles to show “clear evidence” that stress from heat waves reduces “sperm count and viability” in bugs.

The researchers say that insects could indeed by used as a proxy for people according to an article published in USA Today.

“Our research shows that heat waves halve male reproductive fitness, and it was surprising how consistent the effect was,” added Sales.

In the study, published in November in Nature Communications, it was revealed that “heat wave conditions (9 to 13 degrees over the typical high temperature for 5 days) damaged male, but not female, reproduction. Heat waves reduce male fertility and sperm competitiveness, and successive heart waves almost sterilized males.”

In addition, the offspring of the dads who endured the heat lived shorter lives.

Dr. Mary Jane Minkin, Clinical Professor of Obstetrics, Gynecology and Reproductive Medicine at Yale University School of Medicine, tells Newsmax that the study results are “interesting and somewhat plausible” when translated to human reproduction.

“One of the big incentives for men to wear boxers is to keep the testes which produce and store sperm, a bit away from the body and cooler,” she says. “Some folks have hypothesized that the reason the testes evolved from being inside the body is to get them cooler. For example, truck drivers who sit on a warm seat all day, can have fertility issues from the heat.

“So, it’s plausible that the researchers are correct. Obviously we need to wait for more data from humans to see if it is really is an effect.”