If global temperatures increase by 1 degree Celsius (C) or more than current levels, each year billions of people will be exposed to heat and humidity so extreme they will be unable to naturally cool themselves, according to interdisciplinary research from the Penn State College of Health and Human Development, Purdue University College of Sciences and Purdue Institute for a Sustainable Future.

Results from a new article published today (Oct. 9) in Proceedings of the National Academy of Sciences indicated that warming of the planet beyond 1.5 C above preindustrial levels will be increasingly devastating for human health across the planet.

Humans can only withstand certain combinations of heat and humidity before their bodies begin to experience heat-related health problems, such as heat stroke or heart attack. As climate change pushes temperatures higher around the world, billions of people could be pushed beyond these limits.

Read more at: Penn State University

This composite map shows land areas that could face extreme heat if the planet continues to warm (indicated in yellow and orange). The darker the color, the longer the projected exposure to extreme heat. (Photo Credit: Daniel Vecellio, Qinqin Kong, W. Larry Kenney and Matthew Huber; composite image by Dennis Maney, Penn State)