PHILADELPHIA (AP) — The eastern U.S. sweated through a second day of early-season heat Wednesday, with some schoolchildren being sent home while others stayed in sweltering classrooms.

Philadelphia shifted to remote learning for students at 57 schools, saying that while the district has made progress, a number of them continue to have inadequate air conditioning.

The heat sneaked up on some Philadelphia residents and had them concerned about electricity bills before summer has even set in, said Lauren Authur, who lives in the city.

The National Weather Service said another day of record heat was expected from the mid-Atlantic to New England before a cold front brings rain later in the week. Daily high temperature records were broken Tuesday in Portland, Maine, at 92 degrees Fahrenheit, and in Boston at 96.

Temperatures were expected to plunge as low as 45 Fahrenheit in Portland and 50 in Boston as soon as Thursday.