Influence of mild cold on 24 h energy expenditure in ‘normally’ clothed adults

Abstract

Ten subjects aged 19–35 years (four men and six women) underwent two measurements of 24 h energy expenditure (EE) in a whole-body respiration calorimeter, one at a temperature of 28° and one at 20°. Choice of clothing was allowed. Dietary intake was standardized and subjects were asked to follow the same pattern of activity during both measurements. Mean 24 h EE was significantly greater at the cooler temperature by 5.0 (SD 5.5) %, with individual differences ranging from 4.6% lower to 12.6% higher. The difference in EE at the two temperatures was similar during the day and the night and occurred even though subjects wore more clothes and used more bedding at 20°. No relationship was observed between response to 20° and body-weight status. In conclusion, the assumption that mild cold is unlikely to affect EE in subjects wearing normal clothing may be incorrect.