It’s normal to feel hot, sweaty and uncomfortable in warm weather, but what’s the best way to cool down? To answer this question, we first need to look at how the body maintains stable internal (core) temperature.
We feel uncomfortable at hot environmental (ambient) temperatures because our bodies are striving to maintain a constant core temperature. When the ambient temperature is too high, we engage in reflexive (things our nervous system does without us realising) and behavioural (things we do) adaptations to try to cool ourselves. The discomfort we feel is the motivation for the behavioural adjustments. Many of us just want to jump in a cold shower. So will this help to cool us down?
From the physiological perspective, core temperature is what our body is regulating. Small changes in core temperature can quickly lead to illness (such as heat exhaustion, fever and heat stroke). We are not consciously aware of our core body temperature. Although the body has sensors that monitor core body temperature, our perception of temperature comes exclusively from skin temperature sensors (temperature rece ptors). These allow us to sense if we are cold, comfortable or hot.
Human biology is remarkable; we maintain a relatively stable core body temperature over a wide range of ambient temperatures. For instance, core body temperature only differs by 0.5⁰C over a wide ambient temperature range (as wide as 12-48⁰C). The body’s ability to restrict core temperature to such a tight range means reflexes to control core temperature need to occur before there is an actual change in core temperature.