Why Do We Sleep Better In The Cold

The reason why we sleep better in cold temperatures is because our body temperature drops when we are exposed to cold environments. The body's thermoregulation system works by regulating heat loss from the skin through vasodilation (dilatation) of blood vessels and sweating. When the environment is colder than normal, the brain sends signals to the hypothalamus which then stimulates the pituitary gland to release hormones such as adrenocorticotropic hormone (ACTH), which causes the adrenal glands to secrete cortisol. Cortisol increases blood flow to the skin, causing the blood vessels to dilate and sweat to occur. This process is called shivering thermogenesis. Shivering produces heat, which helps maintain core body temperature.