Implications of lower indoor temperatures – Not cool for cold susceptible individuals across both sexes

Wider temperature ranges in buildings can reduce building energy use and prevent shortage of energy availability. However, humans do not perceive temperature equally and a general lowering of indoor temperature may in particular impact susceptible individuals. The discrepancy between individuals has been ascribed to sex differences, but is not well understood and could relate to heterogeneity in endogenous heat production or other personal parameters. We, therefore, evaluated individual thermal responses including physiological measurements of metabolic heat production in both men and women, identified, and via experiments, verified as cold sensitive or cold resilient. On average, the cold sensitive group had an 18 % lower resting metabolic rate compared to the cold resilient group when controlling for clothing and other important parameters for heat exchange. We observed a 0.9 °C difference in neutral temperature between sexes, but no difference in thermal perception or skin temperature. We concluded that cold susceptibility is not simply a matter of perception, but relates to a measurable difference in endogenous heat production. Currently mandated temperature setpoints at workplaces or recommended household temperatures do therefore not seem to discriminate between sexes as a result of sex-related differences in physiology, but they might have negative implications for cold sensitive individuals.