Dogs and residents enjoy the water at Barton Creek Pool June 27, 2023 in Austin, Texas.
Suzanne Cordeiro | AFP | Getty’s paintings
The heatwave in Texas has brought no relief.
For 2 weeks in a row, Del Rio’s high temperatures topped 100 degrees Fahrenheit on daily basis – peaking at up to 115 F.
Equally worrisome is that overnight temperatures set records and brought no relief. For all but someday, the lowest temperature in Del Rio was no less than 80 F, in line with National Weather Service data.
Warm at night disturbs sleep and prevents the body from recovering and cooling down, making minimum temperatures a critical indicator of the severity of a heatwave, experts say. In lots of parts of the country, the nights warm up faster than the days — an insidious threat to human health.
“There are numerous health impact studies that show that nighttime temperatures are especially vital,” said Ben Zaitchik, a professor in the department of earth and planetary sciences at Johns Hopkins University who studies extreme heat. “The body’s amassed heat stress can result in all sorts of complications, and the body’s ability to calm down at night could be critical.”
Texas state climatologist John Nielsen-Gammon said temperatures during this heatwave in the state threatened records at each ends of the spectrum – including highs and lows – in urban centers.
“We had a number of stations, mostly urban, that were approaching periods with record minimum temperatures – San Antonio and Houston,” he said.
Nielsen-Gammon said several areas, including Midland, San Angelo and Del Rio, have set records for average weekly temperatures, an indicator of the length and severity of this heatwave, which was triggered by an prolonged stretch of high pressure.
Kristie Ebi, a professor at the Center for Health and the Global Environment at the University of Washington who specializes in heat and climate change research, said heatwave deaths typically begin after 24 hours as stress builds up in the body. .
“It takes some time for our heart to warm up before you see something like a heart attack,” she said. “We have now behavioral mechanisms – it’s hot, we’re trying to search out a spot to chill down. We have now physiological mechanisms – sweating. There’s an actual effort to lower core temperature on the behavioral and physiological sides.”
Ebi said high nighttime temperatures and a protracted heatwave in Texas were of particular concern.
The costs related to heat are sometimes underestimated as the cumulative stresses can exacerbate underlying health conditions. Once the heatwave is over, scientists will compare death figures with previous years, control for other aspects, after which count the number of “excess deaths” – individuals who otherwise would not have died had it not been for the extreme temperatures.
“A really small proportion of death certificates during a heatwave recorded ‘heat’ as the cause,” Ebi, who studies heat deaths, adds that, on average, about half of the extra deaths come from heart problems.
Climate change is causing temperatures to rise in Texas. Average each day minimum temperatures increased from 51.9 F in 1970 to 54.2 F in 2020—a change of about 2.3 F, which is roughly in line with the state’s overall warming rate.
“Every little thing goes up at about the same rate – each day lows, each day highs, winter versus summer,” Nielsen-Gammon said. “We are actually 2 degrees above the twentieth century average for all seasons.”