Cold Exposure and Metabolism

Physiological Effects of Cold Exposure

Cold exposure activates brown adipose tissue (BAT), which is responsible for non-shivering thermogenesis and can increase metabolic rate, according to the American College of Physicians, as reported in Cell Metabolism 1, 2.
The thermoneutral zone for humans is around 28-32°C, and housing at lower temperatures (20-22°C) increases energy expenditure by approximately 30% above basal metabolic rate, as found in studies published in Nature Metabolism 3.
Cold exposure stimulates both shivering thermogenesis by skeletal muscle and non-shivering thermogenesis by brown and beige fat, as demonstrated in research published in Nature Metabolism 3.

The World Health Organization (WHO) recommends indoor temperatures between 18-24°C for optimal health and comfort, as stated in Environment International 4.
The optimal relative humidity in indoor air for health and work performance is between 40-60%, according to guidelines from the National Institute for Occupational Safety and Health, as reported in Environment International 4.
Putting on a sweater allows indoor temperature to be lowered by 2°C without reducing thermal comfort, as suggested by the American Society of Heating, Refrigerating and Air-Conditioning Engineers, as reported in Environment International 4.

Cold exposure during sleep may disrupt normal sleep patterns, as moderate heat or cold exposure has been found to decrease sleep quality, according to the National Sleep Foundation, as reported in Environment International 4.
Sleep deprivation blunts the normal nadir body temperature during sleep by disrupting circadian rhythm regulation and altering thermoregulatory mechanisms, as found in studies published in medical journals, although the specific guideline society is not specified 5.