When the Simpsons read the book How to cook humans found in the aliens’ spaceship where they were guests, they feared the worst. Fortunately, it went well for them. By now, you no longer need a cookbook for baked human. In many European countries you only have to go out on the street to be cooked or roasted, also in our own Nijmegen. And because cooked people do not walk so easily, the first walking day of the Nijmegen Four Days Marches has been cancelled. Quite rightly so: at such temperatures, the risk of overheating real and life threatening.
The funny thing is, with a fever, the body temperature can also rise above 40 degrees, but without danger. The underlying cause of a fever may be a problem, but the fever itself rarely is. But in people who become 40 degrees due to overheating, the mortality is high. Even if acted quickly, 10 percent die. The difference is that when you have a fever, the thermostat is set to 40 degrees. When the fever rises, people are cold and shivering: their body wants to warm up.
When the body has reached a temperature of 40 degrees it comes to rest – it has reached its new normal. Often people don’t even feel that bad. Only when the disease disappears does the thermostat go down again. Then the body starts to sweat to cool down and thus returns to normal body temperature.
But with heat stroke, the temperature of the body rises, while the thermostat simply remains set at 37.4 degrees. The body tries to get rid of the excess heat by sweating, but at high air temperatures this is not possible.
Persistent sweating causes a person to quickly lose fluids and salts. The blood thickens and flows less well, causing insufficient blood and oxygen to reach the organs. Blood clots form and organ cells die. Due to the death of organ cells, all kinds of breakdown products also enter the blood, which accelerate this process, resulting in life-threatening multi-organ failure. This mainly damages the brain, heart and kidneys.
As Dutch people we have little experience with heat waves and that is an extra risk. We are not used to adapting our behavior to heat and recognize the complaints of overheating less. Overheated people may behave confused, aggressive or irritated, faint or have a seizure. They feel hot and limp. But also headaches, palpitations, nausea and vomiting are symptoms. What to do then? In the shade, drink a lot and cool, cool, cool. And immediately seek medical attention.
But good news: heat gets used to it. The more you experience hot weather, the better your body can tolerate it. Acclimatization to a warm environment usually occurs after 7 to 14 days of at least two hours of daily heat exposure. Unfortunately: air conditioning reduces the development of heat tolerance. In addition, air conditioning consumes an enormous amount of energy, emits extra heat into the outside air and thus exacerbates global warming. Anyone who always turns on the air conditioning really turns into a climate changer.
Rinske van de Goor is a general practitioner