It is an annual ritual in most Indian homes. With the onset of summer it is time to bring the rusty, rickety old coolers down from the terrace and get them repaired. The reason is obvious – it is difficult to live through the hot, sweaty Indian summer without an air cooler. But did you know that the human body has its own cooler as well?

Think of the times you have travelled in a car. How hot the vehicle engine gets after a long journey. Similarly, as our bodies chug along they produce heat in the process.
They normally maintain a temperature of 98.6 degrees Fahrenheit (37 degree Celsius) and become feverish if it rises above this point.

Unlike a car engine, however, our bodies have a system to check “overheating”. This is done with the help of sweat, which serves as a coolant.

Why do Humans Sweat?
Why do Humans Sweat?

How does sweat cool?
Try this out. Put a small drop of water on the back of your hand. Then place your mouth close to your hand and blow hard. That spot will gradually feel cool. This is because the water begins to evaporate with your blowing and produces a cooling sensation.

The inbuilt cooling system of the body uses the skin and blood for its functioning. The blood warms up as it passes through muscles and tissue. It carries the extra heat to the surface of the skin, which triggers the sweat glands in the skin to produce sweat – a combination of water (usually about 99 per cent) with small amounts of salts and amino acids dissolved in it.

The sweat escapes through tiny pores on the skin, evaporating as it reaches the surface. As the sweat evaporates, it cools the skin beneath.

In fact, a pearl-sized bead of sweat can cool nearly one litre of blood by 1.8 degree Centigrade (one degree Fahrenheit).

Why do we sweat more in summer?

Why do Humans Sweat? [Illustration by Shinod AP]
Why do Humans Sweat? [Illustration by Shinod AP]

Have you ever wondered why you sweat more on hot summer afternoons? Actually, the human body sweats all the time, even when we are sleeping.

But when we exercise or perform some strenuous work we sweat more as the body gets heated up faster. As a result, we sweat more during summers and less during winters. The rate of sweating is directly related to our body temperature.

Remember, the more you sweat the more you lose water. So, the next time you go out in the sun, make sure you drink enough water because, like the room cooler, the system under your skin needs water to function.

437 words | 4 minutes
Readability: Grade 6 (11-12 year old children)
Based on Flesch–Kincaid readability scores

Filed under: 5ws and h
Tags: #indians, #engines, #temperature, #sweat

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