Thermal sensation is a concept that refers to how humans react to various environmental conditions. These conditions cause certain sensations in the body that lead the person to “feel” heat or cold.
It should be noted that the Latin word sensatĭo came into our language as a sensation . The concept is associated with the effect or impression that something causes in a person through the senses . Thermal , for its part, is an adjective that mentions what is linked to temperature or heat .
The dry temperature , as well as the speed and humidity of the air are factors that affect the thermal sensation. The clothes a person wears and the food they eat, on the other hand, determine the individual thermal sensation.
Reactions to thermal sensation
When a high thermal sensation is recorded, a subject feels very hot . You can try to lose this heat by minimizing physical activity, protecting yourself from the sun's radiation, or exposing yourself to the air moved by a fan.
On the other hand, if the thermal sensation is reduced, the person will feel cold . In this situation, you can produce heat by wearing clothing that provides thermal insulation, eating high-calorie foods, or doing physical activity.
Although there are personal issues that define the thermal sensation that each person experiences, the general characteristics of the atmosphere affect all people. That is why the thermal sensation, expressed in degrees, is usually disseminated as meteorological information in the media.
The body mechanisms
It is important to highlight that the body uses various mechanisms to exchange heat with the environment (that is, to absorb or dissipate heat). Radiation , convection , evapotranspiration and conduction allow humans to gain or lose heat depending on the case. Let's see below a brief definition of each of these concepts:
- Radiation : a heat exchange takes place between two bodies, for which it is necessary that each of them be at a different temperature . An important aspect to note is that the bodies should not come into contact . In the case of human beings, given that it is most normal for them to cover a large part of their body with clothing, this exchange can only occur through those areas that are bare or that have not been covered excessively.
- Convection : when air comes into contact with the skin, it goes through two very defined changes, which are an increase in volume and another in temperature. This phenomenon leads to a loss of density, which results in it rising and being replaced by air with a higher degree of freshness. When the temperature of the air is higher than that of the skin, then a process takes place that can simply be described as the inverse of that just exposed. As in the case of radiation, this exchange mechanism related to thermal sensation affects the less covered or directly naked parts of the body.
- Evapotranspiration : evaporation occurs on the skin if the amount of heat exceeds 2450 kilojoules per kilo of water (this heat comes from the body itself). Two factors that influence this exchange are air speed and relative humidity .
- Conduction : If we do not cover the skin or if we wear light clothing, and we come into contact with a body that has a different temperature than ours, a heat exchange takes place by conduction. Needless to say, this does not happen very often, since the normal thing in modern societies is for human beings to cover their bodies with a lot of clothing and their feet with thick shoes. Yes, it can occur in privacy, at times when two people are sleeping together, for example.