A group of British researchers believe warmer room temperatures are contributing to ballooning obesity rates.

The analysts, mostly England-based scientists, reported in a Jan. 24 article in the journal Obesity Reviews that excessive exposure to warm indoor temperatures may cause us to lose the natural fat-burning tissue, known as brown fat that we activate when we’re cold.

“All this time spent in toasty interiors may be affecting the levels of brown fat we carry,” Dr. Fiona Johnson, the report’s lead researcher and a fellow at University College London, told The New York Times. “It’s kind of ‘use it or lose it,’ …If you’re not exposed to cold, you’re going to lose your brown fat, and your ability to burn energy will be affected.”

Despite the misleading word ‘fat’ in its name, brown fat—which scientists recently found prevalent in the upper back and necks of most adults—consumes our calories when we are inside rooms with temperatures in the low 60s or less.

Residents in the U.S. usually keep bedrooms set around 68 degrees, according to the Times.

Central heating became common in developing countries including the U.S. and U.K. around the 1960’s, and Johnson said that a “casual link” may exist between the increased room temperatures and rising obesity cases.

But all is not lost—Johnson said individuals might be able to regain brown fat by lowering their room temperature.

To date, researchers have not tested the correlation between colder indoor temperatures and weight loss on humans, but similar tests on mice—which carry high doses of brown fat—found that rodents exposed to chronic cold did lose weight.