A dangerous and deadly heatwave is gripping nearly more than half of the U.S.
Tens of millions are set to broil in record-setting high temperatures this weekend, with heat advisories or warnings in effect from the Midwest to much of the East Coast.
The heatwave is already blamed for at six least deaths.
Temperatures are expected to range from the mid-'90s to the triple digits, with the heat index making it feel as hot as 100 to 115 degrees (46 deg C).
According to Reuters, the gargantuan heatwave hunkered down over the central and eastern United States on Saturday, sending residents to cooling centres and inflicting on Washington a heat index of 106 degrees F (41 C) with even steamier conditions in the forecast.
Nighttime temperatures have remained so high in the heatwave, which started midweek in the Midwest, that Rockford, Illinois, for the first time since 1918 matched its all-time record by failing to fall below 80 degrees F (27 C) on Friday.
High temperatures combined with high humidity make it feel even hotter, called the heat index.
“Heat stress tends to have a cumulative effect so if you’re not recovering at night, especially if you don’t have an air conditioning unit, you’ll accumulate more heat stress,” Lamers said.
“When it stays warm overnight, it provides a higher launch for temperatures the next day,” he added. By midday, Saturday, Boston’s heat index was 102 F (39 C) and forecast to rise to 105 F (40 C) by late afternoon.
New York’s heat index was 100 F (38 C) and forecast to rise to 110 F (43 C), and Washington’s was 106 F (41 C), expected to climb to 111 F (44 C), Lamers said.