John Applewhite, 34, told authorities he had just finished a 13-hour shift and was heading to dinner in East Hempstead, N.Y. when he was decked by a man who got out of a black BMW, the New York Daily News reported Wednesday.
Police are reviewing surveillance video and searching for the attacker.
Applewhite was flown back to Florida with a black eye, broken jaw and several fractures.
"They're going to put a plate in my face and wire my jaw," he told the Daily News from his hospital bed in Lakeland, Fla.
Applewhite's family is furious his act of generosity was met with cruelty.
"John is such a sweet person and he certainly doesn't deserve this," said his sister Mary Anne.