The text explains why high temperature and high humidity are a deadly combination for humans. Discuss what would happen if the body's natural temperature regulation mechanism stopped working.
Evaporation of water (sweat) plays an important role in maintaining human body temperature. In a situation where water no longer evaporates from the skin and the temperature of the surrounding environment is higher than the human body temperature, we inevitably overheat. Our inner furnace cannot be turned off.
When the air temperature exceeds , our skin starts to evaporate water to maintain its own temperature at a safe level, mainly in the form of perspiration. This system works until the "wet thermometer" also reaches . The temperature of the wet thermometer takes into account the cooling effect of the water evaporating from the thermometer, so its reading is much lower under normal conditions than the normal ("dry thermometer") temperature, what we can hear from the weather report.
If the temperature of the wet thermometer exceeds 35 degrees, the air is so saturated with water vapor that sweat no longer evaporates. When our body can no longer expel heat, its temperature begins to rise regardless of how much water we drink, how hard we try to stay in the shade, or how much we try to be inactive. Unrelieved, death follows, which primarily affects the very young, the very old, or people with health problems.
Wet-bulb temperatures exceeding have not been reported yet, but there are some reports that they are beginning to occur in Southwest Asia. Climate change may be accompanied by the prospect that some very densely populated regions of the globe will cross this threshold before the end of the century (especially the Persian Gulf region, South Asia, and probably also the Great China Plain). Together, billions of people live in these regions.
