I found this passage interesting (about the impact of climate controlled environments on resting metabolic rate) > Changes in ambient temperature may also expl

I found this passage interesting (about the impact of climate controlled environments on resting metabolic rate) > Changes in ambient temperature may also explain some of the observed change in body temperature over time. Maintaining constant body temperature despite fluctuations in ambient temperature consumes up to 50–70% of daily energy intake (Levine, 2007). > Resting metabolic rate (RMR), for which body temperature is a crude proxy, increases when the ambient temperature decreases below or rises above the thermoneutral zone, that is the temperature of the environment at which humans can maintain normal temperature with minimum energy expenditure (Erikson et al., 1956). > ... Thus, the amount of time the population has spent at thermoneutral zones has markedly increased, potentially causing a decrease in RMR, and, by analogy, body temperature. Source: https://elifesciences.org/articles/49555 https://elifesciences.org/articles/49555