How Much Heat is Too Much Heat? 

With temperatures soaring across the globe, it is natural to wonder what degree of heat would  incapacitate the human body. 

29 May 2024

By Khushi Maheshwari 

Stating that it is hot in India, would not do justice to the sentiment of Indians grappling with the scorching heat. Parts of India have been under a prolonged heatwave, mostly in the north; on Sunday, 26th May, Phalodi in Rajasthan recorded a scorching 50 degrees Celsius.

The Indian Meteorological Department (IMD), the country’s weather bureau, has issued a red alert for the following regions: west, Uttar Pradesh, Gujarat, Chandigarh, Haryana, Rajasthan, Punjab and Delhi. It has been requested that residents of these states take the appropriate safety measures to shield themselves from the intense heat. 

Maharashtra is experiencing extreme heat, to the point where officials in Akola have implemented Section 144 of the Criminal Procedure Code (CrPC) until 31st May in anticipation of a potential heatwave.

There are hot spots all across the world, including Pakistan and some areas of the United States. A lot of people are wondering how hot is too hot given the current conditions. And what happens if the body can no longer withstand the heat?

What degree of hot is too hot? 

The response to this issue, according to experts, goes beyond the temperature displayed on the thermometer. Humidity and the temperature of the “wet bulb” are major factors. The lowest temperature that may be attained by evaporating water into the air at constant pressure is referred to as the “wet bulb temperature” in meteorology. This temperature has an impact on comfort, agriculture and weather patterns since it helps measure humidity and determines how much water can evaporate into the air.

A person who is at rest, wearing little clothing, in a very dry room (10% relative humidity), and who drinks water constantly is likely to avoid overheating in temperatures as high as 115 degrees Fahrenheit, or 46.1 degrees Celsius, according to a 2014 study by Ollie Jay of the Thermal Ergonomics Laboratory at the University of Sydney.

According to a different study published in 2021, the human body can no longer dissipate heat, and our core temperature rises when the atmospheric temperature reaches 122 degrees Fahrenheit, or 50 degrees Celsius.

The highest temperature that a human organism can withstand, according to a more recent study, is 95 degrees Fahrenheit (35 degrees Celsius) at a moist bulb. Here is an illustration of air temperature and wet bulb temperature: The wet bulb temperature is 30.5 degrees Celsius when the air temperature is 46.1 degrees Celsius and the relative humidity is 30%. However, the wet-bulb temperature is approximately 35 C when the air temperature is 38.9 C and the relative humidity is 77%.

According to research, the body finds it more difficult to handle heat in an atmosphere that is higher in humidity. They discovered that sweat has a harder time evaporating off the body and cooling a person when there is more water in the atmosphere.

They discovered that because humans are unable to control their body temperature, they cannot survive in extreme heat or humidity. “You can still sweat, but you’re not going to be able to cool your body to the temperature that it needs to operate at physiologically,” said Colin Raymond, a postdoctoral researcher at NASA’s Jet Propulsion Laboratory who studies extreme heat, in an interview with Live Science.

It’s crucial to understand that death cannot occur right away from a moist bulb temperature of 35 degrees Celsius. Research has shown that a temperature like that would be unsurvivable, stretched out over about three hours.

People’s resting metabolic rate, or the amount of energy required to function at rest, increases when the wet bulb temperature becomes too high.

What happens when the human body cannot endure the heat? 

Medical professionals warn that people may begin to breathe more heavily and that their heart rates may increase. A person’s core temperature rises when their body is unable to expel extra heat, a condition known as “heat stress.” Confusion, nausea, headaches, dizziness and fainting may ensue from that.

According to Lewis Halsey, a life and health sciences professor at the University of Roehampton in England, humans are usually quite good at adjusting to heat, up to a point. Halsey has done research on the maximum amount of heat that the human body can withstand.

Nevertheless, heat will denature proteins and harm the brain irreversibly if the body is unable to handle it. As stated in an article published in India Today, “the human body can turn into a scrambled egg.”

Again, though, it’s crucial to remember that this might only occur gradually. It doesn’t happen right away.

Excessive temperatures have been demonstrated in studies to have an impact on nearly every component of the human body. It has been shown that your brain may have trouble processing information when the temperature rises. People who experience this decline in cognitive function run the risk of making poor decisions and suffering self-harm or falling. Heatwaves have the potential to seriously inflame the brain in some situations.

In addition to the brain, the heart is also impacted. According to Stephen Cheung, a senior research fellow at Brock University in St. Catharines, Ontario, this is because your body tries to cool itself by trapping more blood outside of your skin.

It has also been discovered that intense heat damages the kidneys and lungs.

Remedies: 

Although there is little one can do to regulate the temperature, one can take safety measures to keep oneself safe. Stay hydrated first and foremost, and supplement with electrolytes if necessary. The body loses a lot of salt and minerals through sweat, and other problems may arise if you drink a lot of water but don’t replenish these lost elements.

Additionally, lower the temperature where you are by eating cold meals, having cool baths and dressing in lighter clothing. When it’s too hot outside, turn on the air conditioning. This, however, could seem illogical because, according to some experts, using air conditioning frequently would make it harder for people to survive without it.

There are additional viable techniques. However, in order to guarantee that the excessive heat brought on by climate change is reduced, nations and governments must act on a broader scale.