Turning the temperature down in the bedroom overnight could lead to metabolic benefits, a new study has found. Researchers noted that sleeping in a cooler environment could help to expand brown fat tissue mass along with activity, leading to better disposal of glucose and other metabolic benefits.

According to researchers, mild and prolonged exposure to the cold, as is often seen in climate-controlled buildings, is optimal for broadening brown adipose tissue mass and activity. Being exposed to warmer temperatures could suppress this tissue.

The study was published last month in the journal Diabetes.

Researchers examined how long-term exposure to moderately cold temperatures affected fat cells in five healthy and lean male volunteers. The volunteers spent four consecutive months sleeping in temperature controlled rooms at the National Institutes of Health Clinical Research Center. During the day, the subjects were allowed to perform their normal activities.

During the study, researchers kept the overnight temperature at around 75 degrees for the first month, followed by 66 degrees for the second month, then 75 for the third and 81 for the fourth. Researchers found double the volume of brown fat and improved insulin sensitivity after the subjects slept in a 66 degree room for a month.

Francesco S. Celi, lead study author, chair and professor in the Division of Endocrinology and Metabolism at the Virginia Commonwealth University School of Medicine, said in a statement, “Our study was performed in lean healthy volunteers, but this is an important proof of concept that brown adipose tissue activation can provide metabolic benefits, such as a reduced risk for diabetes.”

According to WebMD, a general recommendation is to keep the bedroom temperature between 65 and 72 degrees at night.