Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors.

* WHAT...Heat index values up to around 100. * WHERE...Calhoun, Eaton, Ingham, Jackson, Allegan, Barry, Kalamazoo, and Van Buren Counties. * WHEN...Until 8 PM EDT this evening. * IMPACTS...Hot temperatures and high humidity may cause heat illnesses. * ADDITIONAL DETAILS...With hot conditions persisting into a fourth day, the cumulative effects of the heat will wear on people so check on those vulnerable to heat.