WHAT TO DRINK AND EAT DURING 

THE HEAT WEATHER ?

The hallmark of our species is its status as an “endotherm”, or the ability to regulate body temperature independently of the environment (sometimes called “warm blood”).

This is because of the constant heat generated by our body as a by-product of internal metabolic and biological processes, namely our metabolism.

How does this work in practice ?

Metabolism, essential to our functioning, includes the breakdown of nutrients in our food, their absorption and transport to cells, and their conversion into energy or "building blocks".
Every chemical reaction related to metabolism produces heat. This heat is beneficial in case of low temperatures, but when the degrees rise outside, we must prevent overheating...

The idea that a cold substance, such as ice cream, ingested in the stomach can help lower the temperature seems logical.

However, the initially cooling effect quickly gives way to the heat generated by the digestive processes required to break down nutrients. The digestion of high-calorie foods then causes a rise in body temperature. Therefore, ice cream is not the optimal solution for cooling down.

And what about cold drinks ?

The heat transfer between a cold drink and the digestive system can indeed influence the temperature, but this is only temporary and depends on the quantity and caloric content of the liquid ingested.

Small amounts of liquid quickly lose their cooling effect by warming the adjacent organs. In contrast, consuming large amounts of cold liquids slows blood circulation, thereby decreasing the efficiency of heat transport.
No wonder high-calorie drinks like sodas will induce a similar effect to ice cream by boosting metabolism soon after consumption.

However, the impression of refreshment remains !

The cooling effect of cold liquids is due more to their ability to rehydrate than to their temperature. However, this requires an ambient temperature lower than ours.

Otherwise, the opposite happens: the surrounding heat is transferred to our body, as when a summer day gives off heat radiated by the sun.
In such situations, sweating is the most effective way to release heat.

It is triggered when our brain detects an increase in internal temperature, thus stimulating the sweat glands which generate sweat and which are distributed over the entire surface of the skin.

When this sweat reaches the surface of the skin, it evaporates, causing local cooling (known as evaporative cooling).

At the same time, the blood near the surface of the skin cools, helping to lower body temperature.
On average, an adult can lose up to half a liter or even a liter of sweat per day.

However, in hot environments, this amount can rise to almost a liter and a half per hour. Therefore, in such conditions, maintaining adequate hydration is essential.

What about drink choices ?

Are there drinks capable of truly refreshing ?

What about alcoholic beverages ?

On a hot summer day, many succumb to the call of an ice-cold beer...but that's a bad idea, because alcohol is a diuretic. By encouraging the loss of water through urine, it decreases our ability to eliminate heat through perspiration...

Surprisingly, drinking hot drinks is an effective way to cool down: drinking a hot drink stimulates receptors in the mouth and throat, triggering sweating. This allows the body to cool down without requiring a large amount of hot liquid.

The ingredients in spicy foods have a similar effect: they also induce perspiration, thus contributing to body cooling. This is why these dishes are so popular in warm climates.

Rather than refreshing frozen pleasures at the time, let's opt for spicy dishes to sweat well and hydrate ourselves !