A comparison of air temperature thresholds for warm thermal discomfort between pre- and post-menopausal women

Our aim was to compare the ambient temperature thresholds for warm thermal discomfort, thermal unacceptability, and preference for cooler environment between post- and pre-menopausal women at different metabolic rates. A total of 38 women (15 pre-menopausal (46 ± 5 years); 23 post-menopausal (55 ± 3 years)), completed up to 3 experimental trials at different metabolic rates (1.2 MET, 1.8 MET, 2.5 MET) generated by intermittent stepping throughout an air temperature ramp protocol. Ambient air temperature thresholds for warm thermal discomfort (thermal sensation rating of +1.5), warm thermal unacceptability, and a preference for a cooler environment, were determined. Skin temperature at 12 points was measured throughout. While a higher metabolic rate yielded a lower air temperature threshold for warm thermal discomfort (P < 0.001), there was no difference (P = 0.61) between pre-menopausal (28.7 ± 2.3 °C) and post-menopausal (28.5 ± 2.4 °C) women, irrespective of metabolic rate. The threshold of thermal unacceptability and the temperature at which a preference to be cooler was expressed were decreased by 1 °C, regardless of metabolic rate in post-menopausal women (P = 0.021; P = 0.049). Mean body T_sk at the thresholds for warm thermal discomfort, thermal unacceptability, and preference for cooler temperature (all P > 0.05) did not differ between pre-menopausal and post-menopausal women. However, the forehead T_sk thresholds for thermal unacceptability (pre-menopausal: 34.5 ± 1.1 °C; post-menopausal: 33.9 ± 1.2 °C; P = 0.005) and preference for cooler temperature (pre-menopausal: 34.2 ± 1.2 °C; post-menopausal: 33.7 ± 1.3 °C; P = 0.025) were lower in post-menopausal women. These data indicate that while the temperature threshold for warm thermal discomfort is unaltered by menopause status, post-menopausal women report an environment to be unacceptably warm, and express a preference for a cooler temperature, at a lower ambient and forehead skin temperature.