* WHAT...Dangerously hot conditions with heat index values up to 112. * WHERE...Dickson, Hickman, Houston, Humphreys, Lawrence, Lewis, Montgomery, Perry, Stewart, and Wayne Counties. * WHEN...Until 8 PM CDT Tuesday. * IMPACTS...Heat related illnesses increase significantly during extreme heat and high humidity events. Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors.