Fertility Experts Warn Against Electric Blankets in U.S. Cold Snap

As freezing temperatures continue to sweep across the U.S., it may be tempting to bury yourself under an electric blanket or heat your haunches with a seat warmer as you drive. But these cold weather comforts could be damaging your fertility, experts say.

Roughly one in six people around the world will experience infertility in their lifetime, according to the World Health Organization. And, despite popular belief, this is not just a female problem: 50 percent of those struggling with infertility are male.

"It's been estimated that approximately 7 percent of all men are affected by infertility, with 10 to 15 percent of infertile men having a complete lack of sperm," Terry Sullivan, managing director at health care company Fertility Family, told Newsweek. "A 2017 study showed that sperm count has declined by over 50 percent in the last 40 years."

Sperm count is just one of the many factors that can cause male infertility. Other factors are poor sperm quality, low hormone levels, testicular failure and obstruction. But what does this have to do with electric blankets?

"Temperature plays a big role in the production of sperm and male fertility due to the high sensitivity of the spermatogenesis process to fluctuations in temperature," Sullivan said. "Spermatogenesis [sperm production] takes place in the testes, and to ensure optimal sperm production, it's important to maintain the testes at a temperature slightly below the body's core temperature."

He continued: "For the production of healthy sperm, the ideal temperature is approximately [95 degrees Fahrenheit], which is about [3 degrees] lower than the body temperature, which is why the testes are contained in the scrotal sac allowing maintenance of optimal temperature."

But exactly how hot is too hot for the sperm will vary among individuals.

"The exact maximum temperature that the male genitals can safely tolerate will vary from person to person," Sullivan said. "However, the testes are sensitive to temperature changes, and the optimal temperature is below core body temperature. Exposure to temperatures higher than this can have an impact on the quality of the sperm you're producing.

"It's generally recommended for those trying to conceive to avoid exposing the testes to any excessive form of heat," he said.

So how can you stay warm without affecting your sperm quality?

"We'd recommend anything that doesn't mean your testes are in the direct firing line of that source of heat for those trying to conceive," Sullivan said. "Normal blankets and throws instead of heated blankets, warm footwear, moving regularly and layering clothing whilst ensuring it's not too tight fitting, especially underwear, are all good alternatives."

Is there a health problem that's worrying you? Do you have a question about fertility? Let us know via health@newsweek.com. We can ask experts for advice, and your story could be featured in Newsweek.