All over the world, summer is associated with heat, water activities, soft drinks and, of course, ice cream. While most of us agree that ice cream and soft drinks are refreshing summer treats, do they really help keep us cool?
To find out, you need to learn a little more about how the body controls its temperature under different conditions. Maintaining the optimum temperature is done through a process called thermoregulation, which involves a delicate balance between heat production and heat loss.
Our species is considered warm-blooded, endothermic, which is the scientific way of saying that we can control our body temperature regardless of the environment. We can do this because our bodies are constantly producing heat as a by-product of internal chemical and biological processes (metabolism).
How does it all work?
This metabolism is necessary for the proper functioning of our body. It involves the digestive processes involved in breaking down the nutrients in food, absorbing and transporting those nutrients to the cells, and converting them into the building blocks or energy required for physical activity.
All chemical reactions that contribute to this can generate heat. This is useful when it is cold, but when the temperature rises outside, we must avoid overheating …
While it may seem logical that the introduction of a cold food, such as ice cream, into the stomach will help reduce the temperature, in fact its initial cooling effect is quickly replaced by the heat generated by the digestive processes necessary to decompose its contents. nutrients. Digestion of high-calorie foods leads to an increase in body temperature. Therefore, ice cream is not the best option for cooling.
But what about cold drinks? The transfer of heat between a cold drink and the digestive system can indeed directly affect the temperature … However, this is only temporary and depends on the amount and calorie content of the liquid drunk.
A small amount of liquid will quickly lose its cooling effect, being warmed by surrounding organs. And a large amount of cold liquids will cause a slowdown in blood circulation, which will make heat transfer less efficient.
As you can imagine, high-calorie drinks such as sodas will have the same effect as ice cream and kick-start our metabolism shortly after drinking them.
However, we had the impression that we had refreshed…
This cooling effect of cold liquids is most likely due to the rehydration they provide. If heat accumulates inside it, the body will try to lose excess heat by transferring it from the vital organs to the surface of the skin, where it is transferred directly to the environment through convection and radiation.
For this, the ambient temperature must be lower than our own temperature; otherwise, the opposite happens and heat is transferred to our body. Just like the heat radiated by the Sun on a hot summer day.
Sweating is our most efficient way of losing heat. This happens when the brain detects an increase in core body temperature, which reacts by stimulating the sweat glands scattered throughout our skin to produce sweat.
Once on the surface of the skin, this freshly inhaled water evaporates, resulting in localized cooling (also called “evaporative cooling”). The blood circulating near the surface of the skin is cooled and helps to lower the core temperature.
On average, an adult can lose up to half a liter or a liter of sweat per day. In hot conditions, this amount can reach almost one and a half liters per hour. That is why it is so important to maintain the body’s water balance in hot weather.
What then to drink?
We have other drinks to try and refresh.
- What about alcoholic drinks? On a hot summer day, many people jump on cold beer in an attempt to cool down … Bad idea, because alcohol is a diuretic. This means that it will promote the mechanisms for evacuating our water in the urine and thus reduce our ability to lose heat through sweat.
- Ironically, hot drinks can be a good way to cool down. Although not intuitive, drinking a hot drink triggers the sweat receptors in the mouth and throat, allowing the body to cool down without having to swallow large amounts of hot liquid. Our blood vessels dilate and help evacuate excess heat. However, be careful not to become dehydrated from excessive sweating.
- Some ingredients in spicy foods have the same effect: they also trigger the sweating response, which allows the body to cool down. That is why these types of foods are popular in hot climates.
So, while cold treats can be enjoyable and certainly refreshing, the best way to sustainably cool down is to spice things up a bit, get sweaty, and most importantly, replenish moisture!
This article is republished from The Conversation under a Creative Commons license. Read the original article.