In addition, regular exposure to mild cold, which the authors call "temperature training," keeps the peripheral vascular system in motion, helping to strengthen the cardiovascular system, they wrote in Trends in Endocrinology and Metabolism.
"Thermal environment affects human health -- and more specifically ... frequent exposure to mild cold can affect our energy expenditure significantly over sustained time periods," they said.
They pointed out that human dwellings -- homes, offices, and even hospitals -- are cooled and heated for maximum comfort, which minimizes the body's ability to control its own temperature. This may increase susceptibility to obesity and its related disorders.
While shivering can led to heat production five-fold above the resting metabolic rate, it's uncomfortable and impedes coordination, the researchers said. However, animal studies have shown that nonshivering thermogenesis can replace shivering thermogenesis by activating brown adipose tissue, generating heat, and increasing energy expenditure.
They called for temperature training as part of a healthy lifestyle, explaining that gradual temperature variations of about 2°C per hour over a range of 17-25°C (62-77°F) can encourage nonshiverving thermogenesis and boost calories burned without making the environment uncomfortable.
The authors acknowledged that sudden exposure to cold can be problematic in older people because it may negatively effect blood pressure and core temperature. But they also said that temperature training could contribute to healthy aging as "cold-acclimatized individuals are less vulnerable to sudden exposures."
"We suggest that regular exposure to mild cold may provide a healthy and sustainable alternative strategy for increasing energy expenditure," they wrote.