Be prepared as a heat wave prepares to scorch the Northeast.

Tyler Roys, a senior meteorologist with AccuWeather, referred to Monday and Tuesday as the “calm before the heat,” with highs both days expected to be in the mid to upper 80s, though humid conditions will persist.

Roys said Wednesday through Saturday is when the heat surges in, with temperatures in Lehighton and Jim Thorpe down to the whole valley to be in the upper 90s to around 100, with the higher terrain a little cooler up to the mid-90s.

The peak of the heat is going to be Thursday and Friday, as highs in the Valley could get toward around 100, said Roys.

“It’s going to be hazy out there,” Roys said. “Very humid out there.”

There won’t be any relief on those evenings either, said Roys, who noted that Wednesday, Thursday and Friday night temperatures will still be in the low to mid 70s.

“Very uncomfortable, downright miserable, especially if you have no AC, or live in an apartment building where you’re stuck on the third floor and only have fans,” he said. “The body is not going to be able to regulate and cool down.”

Roys added, “In terms of heath-related illnesses, it’s the nighttime that’s looking to be the biggest culprit or time for that to really spike.

“If you have to be outside in the middle of the day, (take) frequent breaks in the day, (drink) frequent amounts of water. At nighttime, if no AC, if there’s cooling centers, go to the cooling centers; if there’s friends who have AC, maybe stay a night or two.

“This is the time we need to help each other out; especially the elderly, the very young (who are) very susceptible to the heat. Checking on them twice a day is the best, making sure they are fine during this stretch.

“Making sure people stay hydrated is probably the biggest thing. It is very easy to get dehydrated.”

Roys said records could be challenged, as highs are expected to be 86 Monday; 88 Tuesday; 97 Wednesday; 99 Thursday; 99 Friday; 94 Saturday; and 88 Sunday.

He noted we do run the risk of a thunderstorm on Saturday and Sunday.

“Will it be a total washout, no,” Roys said. “As far as festivities going, people need to keep an eye to the sky and to the phone for any alerts that come through.”