The Earth is Heating up

In the face of climate change, which has resulted in an increase in extreme heat, a number of scientists have identified the temperature and humidity that the human body can tolerate. According to specialists, healthy humans can only survive for six hours below a threshold temperature of 35 degrees Celsius and 100% humidity, or 46 degrees Celsius and 50% humidity. Sweat, the major instrument for lowering the body's core temperature, can no longer evaporate from the skin at the aforementioned temperature, humidity, and duration combination. Heat stroke, multi-organ failure, and even death can result from this disorder.

The "wet bulb temperature" is the critical equilibrium point between temperature and humidity that humans can endure. "Wet bulb temperature has occurred dozens of times, mostly in the South Asian region and the Persian Gulf," NASA's Jet Propulsion Laboratory's Colin Raymond told AFP on Tuesday (8/8/2023). Raymond, who conducted this investigation, revealed that there were no mass injuries as a result of this chain of events. After all, the incident only lasted about two hours. To be sure, environmental factors such as El Nino and rising sea surface temperatures have influenced the prevalence of wet bulb temperatures in recent years.

Even if there are signals for the maximum temperature and humidity that the human body can withstand, according to Raymond, the threshold for intense heat might sometimes vary for each person. It is determined by age, general health, social and economic considerations, and so on. As an example, almost 61,000 people were believed to have died in Europe due to heat waves last year. The weather was quite hot at the time, but scientists say the level of humidity in the air was still below the critical wet bulb temperature, which is considered threatening to human life.

As global temperatures rise, where on July 3, 2023, it set a new record for the hottest temperature on Earth, reaching 17.01 degrees Celsius, experts advise us to be more cautious in the future as more and more people die as a result of hot weather. The frequency of catastrophic heat waves has more than doubled in the last 40 years, according to Raymond's notes with his team. "Increasing the frequency of these events could be a serious danger from climate change," Raymond said. Daniel Vecellio, a researcher from Pennsylvania State University in the United States, thinks that under present climate change conditions, some areas of the world will reach lethal wet bulb temperatures within the next five to seven years.

According to wet bulb temperature researcher in the South Asia region, Joy Monteiro, through her research published in the journal Nature, most of the deadly heat waves in her research area are below the temperature threshold that humans can tolerate, i.e., below 35 degrees Celsius. These studies demonstrate that the human body's resilience to hot conditions varies greatly between individuals.

According to Ayesha Kadir, a doctor and health adviser with the non-profit organization "Save the Children", there are many groups that are particularly vulnerable to hot temperatures. "Children, the elderly, and people who have intense outdoor activities during extremely hot weather are the groups most at risk," he stated. Children's bodies, according to Kadir, are not yet capable of regulating high body temperature swings like healthy adults. Meanwhile, the number of sweat glands declines substantially with age in the elderly.

"In Europe last summer, nearly 90% of heat-related deaths were among people over the age of 65. Small children are also vulnerable because they have a lower ability to regulate their body temperature," Kadir noted. Apart from the vulnerable populations mentioned above, people with financial constraints, such as a lack of access to drinking water and restrooms, are also in danger of dehydration. "People who are least able to protect themselves from extreme climate change, like other effects of climate change, will be the most victims later," Raymond stated.