A dangerous heatwave is threatening large parts of the US south-west, with millions of people under a heat advisory for the second week in a row. On Tuesday, temperatures were forecast to rise to 102F in Sacramento, California, and on Wednesday to 111F in Phoenix, Arizona. The sweltering heat is expected to reach the east coast by Friday.
El Niño: how the weather event is affecting global heating in 2023 Read more Health experts and climate scientists described the effects of extreme heat on the human body, which populations are most at risk and ways to mitigate it. What is heat stress and what causes it? It occurs when the body experiences a buildup of heat, at a level that is more than what it can release. “The human body has this fantastic ability to cool through sweat evaporation,” said Uwe Reischl, professor in the school of public and population health at Boise State University.
But even when the body is producing sweat, the evaporation can be limited due to humidity in the air. Another factor that causes body temperature to increase is when a person wears clothing that prevents sweat from being released from skin. And when the body doesn’t have enough water, it becomes dehydrated to the point that it isn’t able to produce sweat any more.
How is it connected to the ongoing heat dome phenomenon? Warm air is able to hold more moisture than cold air. “So the warmer the heat dome, the higher humidity levels,” said Reischl. Urban environments with lots of build.
