(NEW YORK) -- The record heat that baked the West Coast for much of last week is arriving on the East Coast early this week and health departments are already preparing for heat-related emergencies.
More than 100 million people in 33 states were under heat alerts Monday morning.
In Philadelphia, where the heat index -- what the temperature feels like with humidity -- is forecast to reach 104 degrees on Monday, the city health department has issued a heat health emergency.
"We'll have over 150 cooling centers open for our residents who need them," Mayor Cherelle Parker said in a statement. "Please call 311 to find a cooling center near you. Check on your older neighbors. Make sure they're safe. If we care for one another, we'll get through this heat wave together."
In addition to Philadelphia, major cities such as Washington, D.C., and Baltimore are under an excessive heat warning -- the highest such alert for heat -- on Monday.
New York City and Boston are under a heat advisory through Tuesday.
Record daily highs are possible in several cities Monday, including Raleigh, North Carolina (projected 101, record 99); Washington, D.C. (projected 100, record 100); Baltimore (projected 101, record 102); Reading, Pennsylvania (projected 100, record 100); Worcester, Massachusetts (projected 91, record 92); and Manchester, New Hampshire (projected 96, record 96).
The record heat will concentrate on the East Coast on Tuesday and could last into Wednesday.
Finally, a cold front will bring an end to the record heat in the East by Wednesday night into Thursday.