If you have read my post from two weeks ago, then you would know almost everything there is to know about water (See Bring Up Water). Water is really important and is essential for the good functioning of many biological processes. With the arrival of summer and its associated high temperature, you will need a lot of it. You will especially need water to ward off any potential heatstroke that may affect you. Its cooling-down action is due to perspiration. Water is such a powerful ally, so much so that it prevents us from being found burnt to a crisp, like earthworms in the street after a massive rainfall. However, its cooling mechanism might not be so well understood by everyone. It is not like putting out a fire, where we just hose down the heat we are emitting. However, it sure is as effective, if not more.
I love playing Beach Volleyball, especially during the summer. I am not personally too fond of cold weather. The heat emitted by the sun feels wonderful on my skin. It seems to get immediately absorbed, even though the transfer is more gradual than immediate. This heat makes me want to have more, and physical activity is a nice way to fulfil this desire. During strenuous activities, our muscles work so hard that they produce heat as a byproduct. They produce, in fact, an enormous amount of heat. Both our physical heat and the ambient heat can work in synergy to provoke alarming body heat levels. To survive, we must get rid of a great amount of it and fast.
This is where perspiration comes into play. As easy as it would seem, water doesn’t just passively pass through our skin. This permeability is quite impossible since the outer layer of our skin prevents such crossing. Our outer skin layer, the epidermis, is actually responsible for the prevention of dehydration. Our body needs to keep as much water as possible because of its use for more functions than just sweat. Also, perspiration needs to be a controlled process. It should only be active when our body heat levels get above our basal thresholds. This is where sweating glands become highly relevant. In humans, we can find two kinds: eccrine and apocrine glands.
So, where do we sweat? The armpits, for sure. Where else? The feet, OK! I can see that. Our back? Yeah! That happens quite often to me after long walks. The inner thighs? Ouch! And yes! The chafing can get pretty bad sometimes. If it may seem like there is not a single area spared from sweating, you are completely right. We sweat everywhere on the body, and this is mostly thanks to our eccrine glands. They can release a saline solution that is mostly composed of water. Even though we can find eccrine glands anywhere on our body, their distribution is denser on our feet and our hands, followed closely by our heads.
Eccrine glands, sometimes called merocrine glands, are releasing this solution through sweat pores. You may already know what sweat pores are, but in case you didn’t: they are holes found in the epidermis where we can find our dear eccrine glands. Here, given the very high concentration of eccrine glands on our palms and soles, you may be wondering why we don’t sweat much there when we get too hot. The answer resides in how they get activated. Most eccrine cells connect to cholinergic nerve fibres activating, in turn, the glands for heat regulation. However, the glands found in our palms and soles are connected to adrenergic fibres. These fibres can activate the glands in the presence of high physical and emotional stress.
Apocrine glands are different from the eccrine glands by both their secretion and how they deliver it. Contrary to eccrine glands, apocrine glands release an oily and opaque substance containing proteins, lipids, and steroids. Instead of delivering their secretion through sweat pores, they deliver it through hair follicles. Hence, the substance usually ends up being mixed with sebum as the hair follicles also host sebaceous glands. You most probably know sebaceous glands from the substance they release, particularly on your face. They produce an oily substance responsible for the waxy finish you get on your skin after a long day.
Now we can’t talk about perspiration without mentioning the infamous odours it seems to carry. The odours, however, are not caused by the sweat itself but by the bacteria that feed off the sweat. It is the waste products, resulting from its metabolism, that produce distinct repulsive smells. There are three main prominent populations of bacteria on our armpits: Staphylococcus, Corynebacterium and Propionibacterium. The resulting metabolite produces a molecule called thioalcohol. Alcohols are highly volatile compounds that can be quickly diffused in the air. Thus, not only do thioalcohols smell horrendous, but also the smells get carried to our nose very quickly.
There exist many approaches we adopt to achieve neutralizing the smell. One of them might be to keep our armpit hair as short as possible. However, shaving might be more culturally acceptable for women than men. If, despite our convention, you decide to part ways with your underarm hair, then you may help to decrease the production of horrid smells. While shaving won’t stop you from sweating (fortunately), it will help reduce bad smells. The presence of hair may help create odours in two ways. First, it helps trap moisture, diminishing heat elimination. This excess heat stimulates the production of even greater amounts of sweat, which provides even more food for the bacteria. Secondly, the hair increases the area where bacteria can accumulate. More bacteria mean even more smelly molecules. Moreover, shaving might not only help in reducing smell, but also help to make the antiperspirant and deodorant products adhere better. This enhanced adhesion can help to curb those nasty smells for good. Yet, even though you finally decided to keep your dear armpit hair intact, using antiperspirants and deodorants can still prove themselves powerful allies.
At this point, you probably realize the importance of keeping the amount of sweat we produced in check in order to keep these odours at bay. Simple strategies can be implemented in our daily routine to help us in that regard. You can start by showering every day to remove excess debris and bacteria on your skin causing the odours. You should also pay extra attention to especially clean the area where you tend to sweat more. If you want to amplify even more the impact of your shower, then you could use an antibacterial soap to wash away as many bacteria as possible. Beware that I am not very fond of this strategy as it may strip away the good bacteria too, leaving your immune system potentially damaged. After your shower, make sure to dry every area, especially your armpits, as humidity makes for the perfect breeding ground for bacteria.
Certain foods and drinks might also induce some bad smells. For instance, spicy foods cause stress on your body and increase perspiration as a result. The aroma of foods, such as onion and garlic, can also be carried in your sweat. Drinking alcohol and coffee also increases perspiration. Intense physical or emotional stress will also intensify sweating. If you think this might be an issue, you might contemplate adopting activities like yoga or meditation to release some of this anxiety. Studies are indicating that these relaxing activities, in some cases, can effectively reduce sweating.
I thank you infinitely for reading this post and if you would like to know more about the mysteries that surround us, please join my subscription list to keep up with my newest content. If you have any questions, please add them to the comment section and I’ll make sure to answer as soon as humanly possible. 
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