Fort Worth (WBAP/KLIF) -The National Weather Service has re-issued its Excessive Heat Warning until 9:00 o’clock Friday) evening for all of north and central Texas.. Forecasters say dangerously hot conditions will continue with temperatures up to 108, and heat index values up to 113. The Weather Service warns extreme heat and humidity will significantly increase the potential for heat related illnesses, particularly for those working or participating in outdoor activities.