Commonly associated with longer days and slower paces, this summer’s record-smashing heat demonstrated a concerning future for our warmest season. From power outages endangering entire neighborhoods and heat-related deaths rising among some of Arizona’s most vulnerable populations, the city of Phoenix found itself in national headlines. As national attention grew, the emerging question became clear: How does anyone live here?
The consequences of extreme heat do not affect Arizona residents alone. Heat made worldwide news this year, including in November when a 23-year-old woman died of cardiorespiratory arrest at a Taylor Swift concert in Brazil where heat indexes that day exceeded 120 degrees.
Jennifer Vanos, a Senior Global Futures Scientist and associate professor in the School of Sustainability at Arizona State University, studies extreme heat and its health impacts. She is the lead author of a paper recently published in Nature Communications: “A physiological approach for assessing human survivability and liveability to heat in a changing climate,” which explores the temperatures at which humans can survive. The paper demonstrates that the current upper-temperature and humidity limits estimates used for human survivability might not paint the most accurate picture of human health impacts on a warming planet.
Read More: Arizona State University
Air temperature survival limits are greatly reduced in humid heat, and more so for older adults. The corresponding wet-bulb temperatures in dry weather are dramatically lower than the previously assumed limit of 95F or 35C. A wet bulb temperature of only 78F on a dry Phoenix summer day would be considered unsurvivable, yet it would take air temperatures of 128F under 10% relative humidity to reach that limit. (Photo Credit: ASU Global Futures Laboratory)