Thermoregulation, or the process that keeps our body’s temperature constant throughout the day, is one that nature has skillfully developed. Thermogenesis (the production of body heat) and thermo-dispersion work together to keep our body temperature in the ideal state, which although around 37°C, varies depending on the activities we engage in, such as eating or practicing in sports, and the time. The role of the hypothalamus and metabolism The two factors that contribute to regulating the body’s temperature are one’s metabolism (which transforms chemical energy into thermal energy) and the hypothalamus, which is considered the organism’s thermostat. The temperature fluctuation during the span of 24 hours is represented by the so-called 'circadian temperature curve'. Sleep and lowering of body temperature Going to bed and falling asleep automatically lowers your body temperature, although that is not the case when the clock hands read 7 a.m. or p.m. While we are asleep, the temperature can drop by up to 2 degrees, as a result of the body’s lower metabolic requirements. Temperature and sleep phases When the temperature drops, the REM phase of sleep may take place. Usually the minimum body temperature peaks occur around 3 or 4 am in the morning, mirroring the maximum peak in the middle of the afternoon. In this phase, our cognitive functions are at the minimum and over the course of history, humans have not developed special defense mechanisms, except those of awakening or suddenly shifting to the REM phase. Mattresses and temperature during the night Body temperature is an essential factor for getting a good night’s rest, which is why there are mattresses that are covered with technical materials such as Outlast® and Coolmax®, to help keep the heat of the mattress constant and our body sleep better.