Heat: from when high temperatures become dangerous

In view of the heat waves of this summer, the European Office of the World Health Organization (WHO) warns to adapt to the high temperatures. In the countries on the Mediterranean, especially Spain, Italy and Greece, which are particularly popular with tourists, it was sometimes over 40 degrees, more heat waves are imminent.

With global warming, the number of heating deaths is likely to increase from year to year, warned the director of the WHO region of Europe, Hans Kluge. He referred to a latest study, which in the summer of 2022 there was more than 60,000 heat -related deaths in Europe. In addition to the fight against climate change, the countries would therefore have to adapt to the new reality in the long term. What do heat waves mean for people? An overview.

A rule of thumb means: it becomes dangerous if the body absorbs more heat under certain conditions than it can release again. Because then the body temperature gets out of control and rises quickly. This limit is very individual and is related to age, state of health, activity and getting used to. At over 30 degrees, the body of many Central Europeans has significantly more stress to cool themselves again than at lower temperatures. Getting used to high temperatures usually takes several days.

Heat means hard work for the human body. Because the organism tries to keep its temperature constant around 37 degrees. Most cells, enzymes, proteins and the immune system then work optimally. All of these processes are disturbed in extreme fluctuations. If the human body temperature increases above 42 degrees or drops below 32 degrees, it can be fatal.

In order to counteract organ damage, the body pulls its cooling up in the heat and releases liquid and salts – sweat. This cools down the skin by evaporating. High air humidity slows down this process. If the body is warmer than the surroundings, it can also radiate heat – like a light bulb heats its surroundings. In high heat, the blood vessels expand, which reduces blood pressure. The heart increases its pumping performance, and breathing can also accelerate. The brain power can decrease due to reduced oxygen supply.

High outside temperatures can heavily strain the cardiovascular system. People with chronic previous illnesses in this area should therefore be particularly careful. With increasing age, the regulation of body temperature slows down and there are fewer sweat glands. Since older people also feel less likely to feel thirsty, there is a risk that they dry out (dehydrating). According to the Maltese auxiliary service, one to two percent too little water in the body can lead to headaches, fatigue, concentration disorders and dizziness.

Among other things, sweat production is lower for children. Babies and toddlers in particular therefore have rather heated problems – a risk is dehydrating here too. People who work physically outdoors or who can help themselves more heavily because of illnesses are at great heat.

If the head without a cap, hat or cloth is exposed to direct sunlight for too long, this can lead to an irritation of the meninges. In severe cases, there is a swelling of the brain. Signs of this can be headache, nausea with vomiting, fever, sometimes also consciousness disorders and seizures.

In the heat, the body’s sweat capacity can reach limits. Then there is a heat build -up: the body temperature rises quickly – often within 10 to 15 minutes – to over 40 degrees or more. As a result, the brain swells and there is a headache, changes in consciousness or unconsciousness. This is a case for the emergency services.

High heat leads to a drop in blood pressure. The consequence is a reduced bleeding in the brain that can lead from a feeling of weak to nausea and dizziness to unconsciousness. This is also an emergency.

Anyone who is physically exhausted in the heat, for example in sports or gardening, usually sweats strongly. This can lead to a lack of liquid and electrolytes such as sodium or potassium in the body. They help to control nerve and muscle function. The muscles react with a lack of electrolytes with cramps or muscle pain.

If the sweat cannot evaporate sufficiently due to little breathable or tight clothing, it clogs the exits of the sweat glands. The result is small, often itchy or burning blisters.