Do you know what he could be coldcalling you with here? If he's raising the flop with a straight draw he has now paired up on the turn, if he's raising this flop with any pair then you're wrong to call his turn bet, and if he's raising you with overcards then you might be drawing to 3 outs (unlikely assuming the preflop action but you can't exclude it as a possibility). I'm not talking about playing scared poker, but I think this is definetly a turn fold.