Obesity crisis: overheated homes and offices adding to weighty problem But temperatures closer to what it is like outside may be more beneficial to health. Simply being colder raises metabolic rate (the speed at which calories are burned) by 30 per cent, while shivering can burn around 400 calories an hour as it increases metabolic rate by five fold. Researchers say although shivering can feel uncomfortable, lowering the temperature so you just feel chilly may an easy option for people who struggle to keep up diets and exercise regimes. "We suggest that regular exposure to mild cold may provide a healthy and sustainable alternative strategy for increasing energy expenditure," said lead author Wouter van Marken Lichtenbelt Thermal comfort in the built environment may increase our susceptibility to obesity and related disorders. Mild cold exposure increases body energy expenditure without shivering and without compromising our precious comfort. More frequent cold exposure alone will not save the world, but it is a serious factor to consider in creating a sustainable environment together with a healthy lifestyle. The Dutch team found that that people who spent six hours at 59F (15C) for a period of 10 days had increased levels of calorie burning brown fat, felt more comfortable and eventually shivered less. Although they do not recommend giving up exercise, they say it could be added to an ongoing regime. Previous Japanese research has shown a decrease in body fat after people spent two hours per day at 17 degrees Celsius (62.6 degrees F) for six weeks. "A little cold a day keeps the doctor away," said Marken Lichtenbelt. In the past century several dramatic changes in the daily living circumstances in Western civilization have occurred, affecting health. For example, we are much better able to control our ambient temperature. Consequently, we cool and heat our dwellings for maximal comfort while miniizing our body energy expenditure necessary to control body temperature. By lack of exposure to varied temperatures entire populations may be prone to developing disease such as obesity. Since most of us are exposed to indoor conditions 90 per cent of the time, it is worth exploring health aspects of ambient temperatures. Tam Fry from the National Obesity Forum said: " A cold environment switches on brown fat deposits which are said to generate 300 times more heat than any organ in the body. They are its natural thermal resource. The heat kept us warm as babies and is still capable of keeping us warm now. Losing weight at the same time is a bonus. Turn your stat down now and see for yourself!  The study was published in the journal Cell Press publication Trends in Endocrinology & Metabolism.