The high temperatures gripping much of the Midwest are nearly certain to persist through the week, and forecasters say the extreme discomfort will soon spread to the East Coast.

The misery was widespread Monday, with the worst conditions blanketing a broad band from Texas to Minnesota and Dakotas. Seventeen states issued heat watches, warnings or advisories.

The heat index easily surpassed 100 degrees in many places, including 126 in Newton, Iowa; 120 in Mitchell, S.D.; and 119 in Madison, Minn.

But few people are hit as hard as the poor.

In Oklahoma, for example, applications from elderly and low-income residents are pouring in for help to pay utility bills. And Chicago officials have opened six cooling centers, many of them in lower-income neighborhoods, along with hundreds of air-conditioned public buildings.