If the man remains unresponsive and soon as possible once it is established the man is breathing normally and there is no life-threatening bleeding to attend to place him on his side into what is known by many as the recovery position. It will help prevent against obstructions caused by vomit, blood or any secretions that may present whilst waiting for help to arrive.
Keep the man warm using a blanket coat or something similar if available. If possible, place an item underneath him before turning him onto his side. It will help prevent heat loss through the underside of the body, especially if the ground is wet.