How much heat can the human body tolerate? Do you know what this deadly heat actually means from a scientific and medical perspective? What is the interaction between internal and external temperatures, and what is the point beyond which body organs stop functioning?

This year, as the month of May progresses, it brings a period of intense heat. The weather displayed varied hues in March and April, but now, in late May, the scorching heat is sweltering. It's also the season of Nautapa. The weather is breaking new records every year. When the mercury touches 45°C or 48°C, we commonly say, "Today is deadly hot." But do you know what this deadly heat actually means from a scientific and medical perspective?

Our body is like a machine, with its own limits of performance. Let's understand how much heat the human body can tolerate. What is the dynamic between internal and external temperatures, and what is the point beyond which body organs stop functioning? In this era of changing climate, heat is no longer just a 'weather' but a 'health disaster'. The best defense is to take this warning from nature seriously and understand the limits of our body.

How much external temperature can the human body withstand?

According to scientists, a healthy human body can easily tolerate outdoor temperatures of 35°C to 40°C. When the outdoor temperature rises above 40°C, the body has to work harder to keep itself cool. If the air is low in humidity, it becomes dry heat. The human body can withstand temperatures of 45°C to 50°C for some time, provided it is regularly hydrated and in the shade. However, if the temperature exceeds 50°C, it poses a serious threat to human life.

Scientifically speaking, the normal human body temperature is 98.6 degrees Fahrenheit. This is equivalent to the ambient temperature of 37 degrees Celsius. Humans can comfortably survive in temperatures as high as 42.3 degrees Celsius. According to science, humans are warm-blooded mammals. Humans are protected by a unique mechanism called homeostasis. Through this process, the human brain's hypothalamus auto-regulates body temperature to maintain it within a survivable range.

The real battle of temperatures

• External temperature: To understand heat, it's important to understand two types of body temperature. External temperature, or environmental temperature, is the temperature measured by the weather station or the temperature we experience in the sun.
• Core temperature: The body's core temperature. This is the temperature of our internal organs, such as the heart, liver, and brain. A healthy person's core temperature should always be between 36.5 and 37.5 degrees Celsius, or 98.6 degrees Fahrenheit.
• The body's cooling system: When the external temperature rises, our brain (hypothalamus) sends a 'command' to cool the body. Blood flow to the skin increases, and we sweat. When this sweat evaporates into the air, the body cools down internally.

What is "wet bulb temperature"?
It's not just the rising temperature that's dangerous, but the real culprit is humidity. Scientists use "wet bulb temperature" to measure this. It's a combination of temperature and humidity that indicates whether our bodies can keep themselves cool by sweating.

Alarm bell: According to scientists, a wet bulb temperature of 35°C—that is, when the temperature is 35°C and the humidity is 100 percent—or 46°C and the humidity is 50 percent—is the limit of human survival. In this condition, the air is so humid that sweat cannot dry. As a result, the body's cooling system fails, and a person can die within a few hours.

What is the effect on the organs?

When the body fails to cool itself, the internal temperature rises. Once it reaches 40 degrees Celsius (104 degrees Fahrenheit) or above, it begins to have devastating effects on the body's organs.

• Brain: Heat can cause swelling in the brain. A person may become confused, their speech may slur, and they may even faint.
• Heart: To maintain blood pressure and cool the body, the heart has to pump much faster. This can cause the heart rate to rise to dangerous levels, increasing the risk of a heart attack.
• Kidneys and Liver: Severe dehydration causes the blood to thicken. The kidneys are unable to filter toxins and begin to fail. Liver cells also begin to be destroyed.
• Cells: Extreme heat can cause the proteins within the body to boil, a phenomenon known as denaturation in scientific terms. Just as an egg coagulates when boiled, this can lead to internal cell destruction.

 PC:Hindi News 18i