Hot summer: should you drink cold or hot?

Between iced tea and the Touareg-style scalding hot tea, preconceived notions run the gamut. One clue, however: Humans are among the homeothermic species that maintain their internal temperature constant, whatever the cost, against all odds. Let's take a look at our thermostat's regulation program...

A program that plays somersault

Our beautiful machine is equipped with temperature sensors. The measurement is transmitted via nerves to the PC, located in the hypothalamus. The motherboard then compares it to the reference value of 37°C. A significant deviation? Warning! The PC starts its somersault program to return to thermal equilibrium. Above 37°C, sweating and peripheral blood vessel dilation occur. Below 37°C, shivering and peripheral blood vessel constriction occur.

The greater the differential, the higher the energy cost. A cost that can cause fatigue, dehydration, disorientation, etc.

So, is drinking hot water in summer a good idea? The differential increases further. So, not only do we make the machine work harder, but we also increase perspiration and therefore the risk of dehydration. And sucking on icebergs? You're fooling the system, which then puts perspiration on hold... while everywhere else but your mouth is hot!

So why do the Tuareg drink boiling tea? First, because neither icicles nor icebergs grow in the Sahara. Second, unlike people living in temperate zones, they are adapted to very high temperatures. Third, they won the innovation prize for the first self-ventilating garment. The layer of air between their two robes allows excess body heat to escape. How? By heating the fabric of the outer robe, the sun creates a temperature differential that triggers air movement. Bingo, the airflow evacuates excess body heat through the collar. Brilliant, right?

Sophie Nicaud

Image by zuzana gazdikova from Pixabay