What happens to the human body at high temperatures?

Very hot weather, lack of ventilation, tight clothing, rigorous exercise… All of these contribute in some way to an increase in body temperature. And if this factor is not properly controlled, it can pose a serious health risk.

Heat exhaustion happens when the body overheats, usually during physical activity in hot environments.

If the body temperature exceeds 40 °C, there is a loss of the ability to cool down and we can suffer from heat stroke, which can even be fatal.

Here’s everything you need to know about the dangers of increased body temperature for our health.

What does extreme heat do to our bodies?

As the body gets warmer, blood vessels dilate. This leads to low blood pressure and makes the heart work harder to push blood through the blood vessels.

At first, this condition can cause mild symptoms, such as itchy skin irritation or swollen feet, as blood vessels become more permeable.

The body reacts to the increase in temperature by increasing blood flow to the skin. This, in turn, “transfers” heat from within the organism to the surface. This process is also related to the accelerated production of sweat, which evaporates and cools the body.

But this excessive sweating also leads to the loss of fluids and minerals, which affects the balance of these substances.

These factors, combined with lowering blood pressure, can lead to heat exhaustion. Symptoms include:

• Dizziness
• Nausea
• fainting
• Confusion
• Cramps
• Headaches
• heavy perspiration
• Tiredness

If blood pressure drops too much, the risk of heart attacks also increases.

Why does the body react this way?

Our body strives to maintain a core temperature close to 37.5°C, whether in a snowstorm or during a heat wave.

This is the ideal temperature for the body to work properly.

But as the weather gets warmer, our cells have to work harder to keep the core temperature down.

It is then necessary to open more blood vessels close to the skin to disperse the heat around us and start the sweating process.

As sweat evaporates, there is a drastic increase in heat lost through the skin.

heat exhaustion

If the body heats up and reaches 39 or 40 °C, the brain issues a command for the muscles to slow down. Fatigue sets in.

Between 40 and 41 °C, heat exhaustion is likely, above 41 °C, the body starts to shut down.

At this stage, chemical processes are affected, cells deteriorate, and there is even a risk of multiple organ failure.

The body can’t even sweat at this point because the blood flow to the skin is stopped, making it cold and clammy.

Heat stroke – which can occur at any temperature above 40°C – requires professional medical help, and if not treated immediately, the chances of survival can be slim.

The best method of cooling people who are in such a severe stage is to dip them in ice water or apply ice packs to the groin and armpits, where the most important arteries are located – but it all depends on how long the body has been in one. elevated temperature.

George Havenith, professor of environmental physiology and ergonomics at Loughborough University in the UK, says that the humidity in the air is critical in determining how much we sweat.

If the humidity is high, our ability to sweat is impaired, and this increases discomfort.

But if the weather is hot and dry, sweating can help.

“We can evaporate a lot of moisture through the skin – but we also have to produce sweat,” says the professor.

“That means having the ability to sweat quickly, but people can be limited by how much sweat they make.”

In this sense, someone who runs at about 15 km per hour in temperatures of up to 37 °C would need to produce four liters of sweat per hour.

Does the heat kill?

Yes, high temperatures can cause deaths.

The biggest cause is heart attacks and strokes caused by the strain of trying to keep your body temperature steady.

Evidence suggests that deaths tend to be caused by higher temperatures in spring or early summer rather than the “peak of summer”.

The first 24 hours of a heat wave, by the way, are the most dangerous.

This can happen because we start to change our daily behavior as the summer progresses and we get used to dealing with the heat better – with fans on and higher water consumption, for example.

Who is most at risk?

People over the age of 60 or those with some long-term conditions, such as heart disease, may have a decreased ability to handle the strain that heat places on the body.

Illnesses such as diabetes can cause the body to lose water more quickly. In addition, some complications of this disease alter blood vessels and the ability to perspire.

Children and individuals with walking difficulties may also be more vulnerable. Brain diseases such as dementia make people unaware of the heat of the moment or make them unable to do anything about it.

Homeless people are more exposed to the sun. And those who live in apartments on the top floors of buildings also face higher temperatures.

What should I do if I see someone with heat exhaustion or heat stroke?

• If the affected person’s body can be cooled down in about half an hour, then heat exhaustion is usually not as severe.
• The first step is to move it to a cool, shady place.
• Then, ask her to lie down and leave her feet slightly elevated (with the support of some object).
• The next step is to drink plenty of water. Sports drinks and sports drinks are also good options.
• Cool the person’s skin – spray or rub in cold water.
• Make sure the environment is ventilated. If possible, use fans and fans.
• Apply cold compresses to your armpits or neck.
• If, after all these measures, the person is not better in 30 minutes, it is a case of heat stroke.
• Treat the situation as a medical emergency and go to the emergency room as soon as possible.

Text originally published here