Q: Who is most at risk?
A: The elderly and children. The elderly make up 36 percent of heat deaths in the past decade, according to the CDC. And of all the excessive heat deaths, 69 percent are men. Also on average, 37 children left in car seats die from heat each year, according to a study at San Francisco State University.
Q: What can you do to stay safe?
A: Drink lots of water; the dry heat in the Southwest evaporates sweat so quickly that people don’t notice they are perspiring and get dehydrated more quickly, Jacks said. Stay in the shade and out of the heat between 10 a.m. and 4 p.m. Use sunblock of SPF 15 or higher. Wear light-colored clothing and light clothing. Reduce use of caffeine and alcohol, which tend to dehydrate, and slow down.
Q: So what’s causing all this?
A: Part of it is normal summer heat spurts, said meteorologist Kenneth James of the Weather Prediction Center in College Park, Md. But there’s another factor and that’s the jet stream.
Normally the jet stream moves generally west-to-east, but when it slows and swings dramatically to the north or south, extreme weather can happen.
What’s happening now is “a really big kink in the jet stream, about as big as you can see anytime, covering the whole western U.S.,” said heat wave expert Ken Kunkel, a professor of atmospheric sciences at North Carolina State University.
To the west of the kink, in Arizona and Nevada, there’s a high pressure system just parked there with stagnant heat, Kunkel said. And to its east are cool — even record cool — temperatures in Texas, he said.
Q: When will it end?
A: The extreme heat should continue for about a week, but it won’t set records, James said.