 RDU Airport recorded a high temperature of 106 degrees in the Triangle on Friday, the hottest day in recorded history for the Triangle. The heat index was also the hottest ever at 118 degrees. Earlier in the day, the National Weather Service issued an excessive heat warning across central North Carolina and the northern Sandhills regions. Records go back as far as 1887 in the Triangle. Heat index didn't really come along until the 1970s. I'm Gail Hurd.