why do we feel hot or cold
Reader PartiallyDeflected wrote in to ask, БSince our body temperature is around 98 degrees, why do we feel hot when itБs 90? Б
Pretty much everything your body does, whether physical (like muscle contractions) or chemical (like some stages of digestion), produces heat as a byproduct. YouБre constantly generating it, and constantly losing it to the environment. The hypothalamus, an almond-sized chunk of the brain that rests deep within its squishy confines, acts as the bodyБs and tries to keep the amount of heatб created and the amount lost close to each other and maintain normal body temperature.
Normally, this is easy enough. Heat seeks, a state where everything is the same temperature as everything around it. ItБs why a bowl of hot soup and a glass of ice water will both reach room temperature if you leave them out on the counter long enough. Usually, the environment around you is cooler than your body, so your little thermostat can just dump the excess heat into it with thermoregulatory processes like (where the heat is lost by evaporation) and increasing through capillaries close to the surface of the skin (where the heat is lost through ).
When thereБs a big temperature difference between your body and your environment, heat flows out of you and into the air pretty easily, and you cool down quickly. When the environment is warmer and closer to our body temperature, though, the heat doesnБt transfer as readily or quickly via radiation, convection, and conduction. YouБre stuck hanging on to some of your excess heat for longer, and you feel hot and uncomfortable (and if the ambient temperature goes higher than your body temp, heatБs quest for equilibrium means that youБll take on excess heat from the environment).
If conditions are hot and dry, the body can deal with these situations by ramping up to get rid of more heat through evaporation. When itБs hot and humid, though, you really feel hot and gross because the high moisture content of the air makes it more for the sweat to evaporate.
If you spend enough time in a situation where the heat you generate or absorb from the environment exceeds the heat youБre getting rid of, your core temperature will rise and you can suffer from. If you compare the feeling of touching a piece of metal versus a piece of paper, the metal will always seem cooler, even if both objects are actually the same temperature. So what gives? It turns out that what we re really feeling as cold when we touch something is away from our skin. Temperature is technically just a measurement of how much atoms and molecules in a given object are moving.
The more movement, the hotter it feels. And since metal is a good conductor, it actually pulls thermal energy away from our skin when touched, causing our thermo-receptive nerves to interpret the loss of energy as the object being cold. So maybe meteorologists should start providing forecasts based on how quickly our bodies will gain and lose thermal energy throughout the day, instead of it being hot or cold. Or, maybe not.
- Autor: Laurel4416
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