An older man should always be treated before a younger man is, as he has more wisdom, age, and if more frail and fragile then a younger man. It is a sign of respect for the older generation and all that they have gone through to treat them first and let them know you appreciate them.
On the current state both patients are in. A younger man's body is more healthy and functional than that of an older man's. Now if the older man is practically on his death bed then the younger man should come first. Mostly because the younger youth are the next generation and those are the ones you want to help the most really. Regardless the old should be helped first because they're the weakest. Unless the younger man was dying or something