Why Does Our Skin Sweat In Hot Weather?

As you’re no doubt rediscovering, your skin does an awful lot for your when it comes to keeping you cool in the summer months. We talked about some of the most prominent ones in last week’s blog, but this week we’re talking about the big one; so why exactly do we sweat, and what good does it do for us?

Why Do We Sweat?

physical activity causes sweating

Human beings have an average of between two and four million sweat glands. Which, if you’ve spent any length of time in ridiculously warm weather, you’ll have no trouble believing! There are two types of sweat glands: eccrine and apocrine. Apocrine glands are found in the skin, breast, eyelid and ear. Most of the ones in our skin are concentrated around our armpits, groin, and around our nipples. From an evolutionary standpoint they’re scent glands, which makes them the source of most body odour.

The eccrine glands are the ones that produce the most sweat, which makes sense given that they’re one of the main ways that our bodies use to regulate our temperature. When we start to overheat, our nervous system kicks our eccrine glands into gear to stimulate sweating. How much we actually produce is affected by a bunch of factors; the environmental conditions, our ages, fitness levels, genetics and even our genders come into play. (Men sweat more than women – sorry, guys!)

We’re talking mainly about hot weather in this particular blog, but we can sweat for lots of other reasons, too. The same principles apply if we’re exercising hard too, but sweating can be in response to emotional stress, for example, or it could be because we’re fighting an illness or infection. Some illnesses – such as fevers – have a tendency to mess with our internal body temperatures, and sweating is our body’s way of trying to regain control.

So essentially, the main reasons why we sweat are:

  1. To regulate our core body temperature in hot climates
  2. To stop ourselves from overheating when exercising
  3. To counterbalance the effect of illnesses on our bodies, which can affect our internal temperatures
  4. In response to emotional stress, for example fear

How Does Sweat Cool Us Down?


First off, the sweat makes your skin feel cooler when it’s wet. After a relatively short amount of time it evaporates from your skin. Now, this is where the science comes in; as it converts from a liquid to a vapour, the exchange takes a certain amount of heat. Therefore, as the sweat evaporates off your skin, each droplet takes a little bit of heat with it, helping you to keep cool.

Nobody likes those muggy days, where the air is warm but the weather is damp. Part of the reason we always feel so uncomfortable on those days is because sweat doesn’t work as well in these conditions. You see, humid air already has water vapour in it and can’t take much more, so sweat can’t evaporate off your body as easily as it can when the air is dry.

Sweat is mainly made up of water, sodium and salt – and as you can imagine, your body uses a lot of water to make and release all this sweat. It’s one of the many reasons it’s a good idea to keep yourself topped up on fluids all throughout the summer, especially when exercising. In consistently hot conditions, we can generate up to 10-14 litres of sweat per day. You’ve got to constantly be replacing the water that your body is expending trying to keep you cool – it’s dangerously easy to get dehydrated otherwise!

Anti-Perspiration Treatments from AP Skincare

Of course, despite the good it does for you, that’s still little consolation when you’re about to make a presentation, teach a class or go into a business meeting with your damp shirt clinging to you, or dark patches under your arms. Some people are even prone to a natural overactivity of their underarm sweat glands, making life a running battle to keep things under control.

At AP Skincare, we’ve got just the thing – our Anti Perspiration treatments can give you back control, helping you feel more refreshed and confident in your daily life.

If you have any questions, or to book yourself in for a treatment, just call 01254 297 000, or email us on enquiries@apskincare.co.uk. We’re here to help!