According to Elite Daily, there may be some health benefits to sleeping in a room at between 60-67°F (15-19°C)
In particular, they cite Temperature-acclimated brown adipose tissue modulates insulin sensitivity in humans. to claim:
lowering your thermostat a few degrees before bed can help decrease your risk of certain metabolic diseases, such as diabetes.
Additionally, colder-sleepers also burned more calories throughout their day, as Gretchen Reynolds of the New York Times writes. In conjunction, these two relationships could lessen the risk of diabetes and other types of metabolic conditions, over time.
However, the first study is very small (n=5 men), leading me to ask the following question:
Does sleeping in "cold" temperatures - e.g. 15-20°C - reduce the risk of diabetes?