This week’s brutal heat and humidity spread from Texas across the Gulf Coast and north into Missouri, Tennessee, and Arkansas on Wednesday.
“It’s miserable,” said Kellie Tortorich, a teacher in Baton Rouge, La., who is out of school for the summer but is caring for two young children while pregnant with a third, according to the New York Times. “We prioritize being outside,” she said as her children, 4 and 6, emerged dripping wet from a splash park, “but it’s been hard at certain times of the day.”
And while coping with a heat wave during the day is pure Hell for some folks, we have another increasingly dangerous element to contend with – overnight temperatures that don’t cool down enough to offer a sufficient reprieve from the oppressive heat, particularly for people without access to air conditioning.
“Most people don’t realize that hot night-time temperatures have been outpacing daytime temperature increases across most populated regions worldwide in recent decades,” Columbia University’s Data Science Institute postdoctoral research scientist Kelton Minor told CNN.
“There are a number of studies on health impacts that show nighttime temperatures are particularly important,” said Ben Zaitchik, a professor in the Earth and planetary sciences department at Johns Hopkins University who studies extreme heat. “The body’s accumulated heat stress can lead to all kinds of complications and the ability of the body to relax at night can be critical.”
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 deaths during heat waves typically start after the 24-hour mark as stress accumulates on the body.
“It takes a while for our heart to become hot before you see something like a heart attack,” she said. “We have behavioral mechanisms — it’s hot, we try to find a place to cool down. We have physiological mechanisms — sweating. There’s a real effort to bring that core temperature down on the behavioral and physiological side.”
As it stands now, temperatures will climb up to 20 degrees above normal for much of the region through at least the weekend, reaching the upper 90s or low 100s in many places, with the heat index – a measure of how heat and humidity make the air feel – soaring even higher.
Hotter nights are a consequence of the climate crisis, scientists have warned. On average, nights are warming faster than days in most of the United States, the 2018 National Climate Assessment found.
And unless planet-warming pollution is curbed, the climate crisis is set to increase exposure to dangerous heat index levels by 50 to 100 percent in much of the tropics and by up to 10 times across much of the globe, according to a 2022 study published in Communications Earth & Environment.
It is likely that, without major emissions reductions, large portions of the global tropics and subtropics would experience Heat Index levels higher than considered “dangerous” for a majority of the year by the end of the century.
Ways to cool down in a heat wave
A heatwave can affect anyone, but the most vulnerable people are:
- older people – especially those over 75 and female
- those who live on their own or in a care home
- people who have a serious or long-term illness including heart or lung conditions, diabetes, kidney disease, Parkinson’s disease, or some mental health conditions
- people who are on multiple medicines that may make them more likely to be badly affected by hot weather
- those who may find it hard to keep cool – babies and the very young, the bed-bound, those with drug or alcohol addictions or with Alzheimer’s disease
- people who spend a lot of time outside or in hot places – those who live in a top-floor flat, the homeless, or those whose jobs are outside
A few tips for coping with the heat
First and foremost, it is important to keep out of the heat if you can. If you have to go outside, stay in the shade, especially between 11 am and 3 pm, wear sunscreen, a hat, and light clothes, and avoid exercise or activity that makes you hotter.
Cool yourself down. Have cold food and drinks, avoid alcohol, caffeine, and hot drinks, and have a cool shower or put cool water on your skin or clothes.
Keep your living space cool. Close windows during the day and open them at night when the temperature outside has gone down. Electric fans can help if the temperature is below 95 degrees Fahrenheit (35 Degrees Celsius). Check the temperature of rooms, especially where people at higher risk live and sleep.
And as always, check on older relatives and neighbors. Remember that heat can kill.
