How hot is too hot for humans?

Record-setting heat waves have gripped the U.S. only weeks into summer, and at least 38 people are suspected to have died from heat-related issues so far this summer.

Record-setting heat waves have gripped the U.S. only weeks into summer, and at least 38 people are suspected to have died from heat-related issues so far this summer. 

Climate change is fueling new heat extremes, and researchers who are racing to better understand the limits of human survival are increasingly focused on determining at what temperature thresholds people can survive without air conditioning and how soon some parts of the world could reach deadly levels. 

Some scientists worry that a widespread heat wave could strike a region without reliable air conditioning and cause a mass death event. And recent research suggests that the threshold for surviving heat is far lower than what some scientists once thought, particularly for older people and in dry climates.

“We can only sweat so much, and older people even less,” said Jennifer Vanos, an associate professor in the School of Sustainability at Arizona State University. 

“Where we live in the U.S., heat deaths should be 100% percent preventable. There should be air conditioning in some location. But, in some parts of the world, that doesn’t exist.” 

https://www.nbcnews.com/science/environment/how-hot-too-hot-humans-record-temperatures-rcna160261

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