The temperatures recorded in these two Asian states already exceed the levels bearable by humans.
- Northern India, Bangladesh and southern Pakistan are the regions that will be most affected by global warming, according to various studies.
- According to AFP, more than 6,500 people have died from heat waves in India since 2010.
The spring of 2022 is that of all extremes in Southeast Asia. In India and Pakistan, the thermometer is chaining records. On April 30, temperatures were between 46 and 47°C. On Wednesday May 11, the thermometer crossed the 50°C mark. However, in these two countries, the weather is also characterized by a high level of humidity. Combined with heat, it can become fatal.
What is wet bulb temperature?
Last January, researchers at Penn State University focused on the maximum temperatures bearable by humans. They found that the threshold accepted until now was in fact too high. Featured in Journal of Applied Physiologytheir work focuses on the “thermometer humid“, indicated by the acronym Tw: “Wet bulb temperature is read by a thermometer with a wet wick on its bulb., they point out. Humidity and air movement affect the measurement obtained. “It represents a humid temperature at which the air is saturated and retains as much moisture as possible in the form of water vapor, and at which a person’s sweat does not evaporate.”, add the authors. The scientific community establishes the maximum wet bulb temperature at 35°Tw, which means that from this threshold, human beings can no longer regulate their body temperature, and are exposed to a high risk of heat stroke and even death. . In their work, they demonstrate that this threshold is actually 31°Tw or even 28°Tw.
Effects, even on young and healthy people
To reach this conclusion, they recruited 24 people aged 18 to 34. All carried out stress tests under varying temperature and humidity conditions: the participants had to walk or pedal slowly. They stopped when the conditions no longer allowed them to advance. After analyzing their data, the researchers found that the critical temperatures ranged from 25° to 28° in hot, dry environments and from 30° to 31° in hot, humid environments. “Our results suggest that in humid parts of the world we should start to worry – even for young and healthy people – when the temperature is over 31 degrees humid.“, says W. Larry Kenney, lead author of the study. However, the wet temperature has already exceeded 35°Tw for several days in the Pakistani city of Jacobabad. And these heat waves are already having consequences: in India’s Maharashtra state, 25 people have died from heat waves since March. According to the World Health Organization between 2030 and 2050, climate change could lead to almost 250,000 additional deaths per year worldwide.
