EXCESSIVE HEAT WATCH IN EFFECT FROM WEDNESDAY MORNING THROUGH THURSDAY EVENING... * WHAT...Dangerously hot and humid conditions with heat index values up to around 110 possible. * WHERE...In Illinois, McHenry, Lake IL, DuPage, Northern Cook, Central Cook and Southern Cook Counties. In Indiana, Lake IN, Porter and Jasper Counties. * WHEN...From late Wednesday morning through Thursday evening. * IMPACTS...Extreme heat and humidity will significantly increase the potential for heat related illnesses, particularly for those working or participating in outdoor activities. PRECAUTIONARY/PREPAREDNESS ACTIONS... An Excessive Heat Watch means that a prolonged period of hot temperatures is expected. The combination of hot temperatures and high humidity will combine to create a DANGEROUS SITUATION in which heat illnesses are possible. Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors.