By Rebecca Anderson,  ACE, Sierra’s Educator and Team Scientist.

Yes, it’s hot. Scorchingly, swelteringly hot. So hot that roads and railroads are buckling.

Much of the mid-west and the eastern seaboard is under an excessive heat warning through the weekend. Actual temperatures are projected to top 100º in many states, but (as anyone in this part of the country knows already) it feels much worse due to the humidity that’s accompanying this heat wave.

Here are a few stats to put this heat wave in perspective:

•Over 140 million people (that’s almost half the whole country) are under a heat warning or advisory.
•22 people have died this week from the heat wave.
•1924 records were set this week alone for the highest minimum temperature.

This means it’s staying hot, even at night. This fact is notable for two reasons:

(1)Hot nights are particularly harmful for human health. Without a chance to cool off at night, people are more likely to suffer from heat stroke and dehydration. This is especially true for those most at risk from heat waves: children, the elderly and the poor. Washington, DC came within a degree of breaking its warmest night on record of a whopping 83º, with the heat index at 100º.

(2)The other factor that makes hot nights significant is that they are specifically predicted as a product of climate change. Minimum nighttime temperatures are increasing faster than daytime highs.

Check out this graphic from Climate Central showing the record minimum temperatures recorded across the U.S. for the month of July:

As if this wasn’t enough, climate scientists tell us we just gotta get used to it. A recent study showed that in 20 years from now, even the coolest summers will be hotter than the hottest summers of the last 50 years.

Doesn’t give us a whole lot to look forward to. I heard on the news that if you’re in New York City, you can go to your local fire department and get a sprinkler head for your nearby fire hydrant. They’ve also put in local cooling centers, so check out the Department of the Environment near you.