When the body is unable to cool itself and it begins to overheat, sun stroke is a likely complication.
The human body controls its core temperature (body temperature) by maintaining a tight balance between heat gain and heat loss.
While we are resting normal core temperature ranges between 36.5°C and 37.5°C (97.7°F and 99.5°F). The hypothalamus, a part of the brain, regulates our core temperature. The hypothalamus is sometimes called the body’s thermostat.
There are several temperature receptors located in different parts of the body, to which the hypothalamus responds by making physiological adjustments to make sure the core temperature is constant. For example, temperature receptors in the skin tell the hypothalamus it is hot, which tells the sweat glands to produce more sweat.
When we do exercise, thermoregulation (temperature control) is a continuous challenge. Metabolism produces heat. The human body is not that efficient – 75% of our energy is lost in heat. During exercise, our core temperature can rise rapidly.
Our bodies have several ways of maintaining thermoregulation.
The human body can be cooled down in the following ways:
Radiation – heat radiates out of our body in the same way it radiates our of a fire.
Convection – when cool air or water crosses the skin the body is cooled.
Conduction – an object that is at a lower temperatures than our body temperature comes into direct contact with our skin – it conducts (draws out) heat from our body.
Evaporation – our bodies produce sweat, as the sweat evaporates it takes body heat with it.
The normal temperature of the skin is 32°C -34°C (89.6°F -93.2°F). Any outside temperature above those ranges will result in the skin producing more sweat to cool the body down.
The following situations, can undermine the body’s ability to thermoregulate through sweating:
Dehydration – excessive loss of water from the body.
Wrong clothing – for sweat to evaporate and take heat with it, the skin must have contact with air. Tight clothing undermines sweat’s ability to evaporate, so the body cannot cool down properly.
High humidity – the higher the atmospheric humidity, the slower water evaporates. In other words, when it is humid sweating is less effective in cooling down the body. The problem is compounded if it is very humid and there is no breeze.