The National Weather Service has issued a heat advisory for New York City beginning Sunday and lasting through Thursday.

Meteorologists say the heat index–what it actually feels like outside–is expected to be at or above 95 degrees. They say on Wednesday and Thursday, the heat index could reach 100 degrees.

The city’s Office of Emergency Management warned of potential heat illness, advising seniors and people with health conditions to stay in air conditioned areas. The OEM says all New Yorkers should avoid strenuous activity and drink plenty of water.

The OEM says city cooling centers at senior centers, libraries and community centers will be open Sunday through Thursday.

(Source: NBC New York)