EE 1 & EE 2 skid steer down with engine compartment door open. EE 1 went to get headlamp, to check tension on alternator belt. EE 1 returned did not see EE 2, EE 1 believed EE 2 was in pick-up. EE 1 looked in rear windshield of skid steer, did not see EE 2. EE1 touched the alternator belt at the same time EE 2 tried to start skid steer. EE 1 felt the belt move and pulled hand back.