Parts of 32 states faced warnings about potentially hazardous heat on Wednesday as the National Weather Service predicted that soaring temperatures would spread east to cities including Washington, D.C., Philadelphia and New York.

The National Weather Service warned that the oppressive heat blanketing the Midwest will expand to the mid-Atlantic, the northeast and the southeast, with many portions of the country possibly facing triple digit temperatures through the weekend.

Temperatures will feel like 100 to 110 degrees or higher during the afternoon hours, the service said.

Heat indexes, which try to gauge how hot it feels, vaulted above 120 degrees in the Midwest on Tuesday: 129 in Newton, Iowa; 121 in Taylorville, Illinois; 122 in Gwinner, North Dakota, and 123 in Hutchinson, Minnesota. Washington, D.C., Philadelphia and New York could face temperatures that feel like 110 degrees. Wednesday could be Chicago's first 100 degree day since 2005,.

At least 13 deaths so far can be attributed to the heat wave, the National Weather Service said. Dehydration and heat exhaustion have also claimed the lives of a number of immigrants seeking to cross the border illegally, the U.S. Border Patrol told msnbc.