During a long heat wave such as this, it’s important to remain hydrated and, when possible, delay strenuous exercise outside peak heating hours. Also, remember to keep your pets cool and hydrated, and never leave a child in a parked car for any length of time.

So, what is a “heat dome”?

“A heat dome is the result of a couple of factors that are coming together. You’ve got your jet stream that is usually very, very far to the north into Canada,” said NBC News meteorologist Sherri Pugh. “You have a building ridge south of the jet. That area acts as a dome, and then under this dome, you have a lot of sinking air. Sinking air is compressed and therefore it warms, and that adds an excessive amount of heat in the dome.
“While it is really hot, it’s not necessarily record-breaking. The challenge with heat domes, and the dangerous part, is the prolonged nature of the heat event. It’s days of heat, and even your nighttime lows don’t get very cool, so you don’t get a chance to cool off.”
During a heat dome, temperatures can be 10 to 20 degrees above average for several days.
So over the course of the next few days, be sure to load up on plenty of water, stay cool, and, most importantly, stay hydrated.