Tropical Storm Fred forms as extreme heat grips the US: Latest

As Tropical Storm Fred takes aim on the Florida Keys, a heat wave is gripping 33 states.

As Tropical Storm Fred takes aim on the Florida Keys, a heat wave is gripping 33 states. A heat wave is spreading to the Northeast as well as parts of the Midwest, South and Pacific Northwest. By Thursday, the heat index -- what the temperature feels like -- could climb to 103 degrees in Boston, 105 in New York City and 109 in Philadelphia.