The National Weather Service in Louisville has issued an excessive heat warning, in effect until 9pm tonight.Forecasters say today's high will range from 96 to 101. Combined with high relative humidity, this will result in a heat index from 106 to 111 degrees.This combination of heat and high humidity will combine to create a dangerous situation in which heat illnesses are likely. The NWS recommends drinking plenty of fluids, staying in an air-conditioned room, staying out of the sun. You should also check up on relatives and neighbors.Forecasters expect somewhat cooler temperatures tomorrow.