 The heat that was plaguing the West Coast is now baking major cities on the East Coast. Philadelphia declaring a heat emergency through Wednesday. Pediatricians warn children are especially vulnerable to heat-related illnesses and extreme heat. A child will come to you because their stomach is hurting or their legs are hurting or their head is hurting. And it will be pretty much all of a sudden. And Dr. Colleen Kraft, a pediatrician in L.A., says kids sometimes keep playing until their systems shut down.