Legs would probably shake a bit, but I could get it done with a cooperative partner. I’m 200 reasonably fit lbs and regularly carry the 140 pound wife without issue.
30% chance my back would give out on the pickup.
30% chance my back would give out some where in the distance
20% chance a Knee or ankle would trick out
20% I make it.
Assuming no Adrenaline.
Carry over my shoulder 50 meters wouldn’t be much of an issue. Picking him (dead weight) off the floor and getting him on the shoulder would be a “no friggin way”.
I’m pretty sure that if I could get the person up there in the first place I could get them 50 meters. I’m 6’, 180 and in good shape. I’m also over 50, though. I’ve got a slightly damaged Achilles tendon that could snap.
The shoulder loading might be awkward, but once I’m under him and have him mounted carrying him that distance would be trivial.
I certainly could. I do lift and carry such weight on occasion. For risk of injury I avoid doing so as much as possible.
I can comfortable carry two of any bagged good on a shoulder up and down stairs or ladders, that’s 120 pounds for most the products I deal with. That’s a steady walk.
One of the guys I occasionally work with is a fire fighter and does fire fighter competition stuff he can run outpace me by quite a bit carrying 3 bags at a time.
Yup. Carried him along with my rifle.
If the person being carried can assist, it is much easier.
Surprisingly, it was more difficult performing a two-man carry of a simulated wounded man while all three of us were in full body armor, helmet and equipped with 7 loaded magazines, rifle, blow out kit, etc. The man being carried is expected to engage hostiles if possible. Wounded and carried, but still able to fire his weapon.
Sure I could do it in a fireman’s carry. It’s designed for men to carry victim’s in emergencies. But they prefer using a stretcher if one is available. I had to practice the fireman’s carry to earn my First Aid merit badge in scouting.
No doubt I’d probably injure myself doing it now. Hope I never have to find out.
here’s a diagram of the steps. The fireman’s carry uses as much leverage as possible. Minimizing the strain of lifting.
http://medical.tpub.com/14295/css/14295_136.htm
The hard part is walking with the person on top of you. 
As ya get older, you have to remember the part of your brain which still thinks you are a (few) decade(s) younger. Could before, and probably could now, but I’d only try in an emergency.
Am I restricted in precisely how I get to pick him up and carry him? Specifically, can I instruct him to get on my shoulders and ride me piggyback? (Or just have him stand up in a position that will let me dive my head between his knees, grab the front of his shins with my hands and straighten up, with him balancing)? If so, sure, and for a hell of a lot farther than 50 meters. Not 50 miles. I’ll say 5 miles no sweat. 10 miles sweaty and tired.
If it’s an unconscious man lying sprawled on the concrete and I’ve got to get him hoisted, I’m not sure I’d ever get him off the ground. I know about the fireman’s carry but I’m not sure I could do it.
I doubt I could lift the person off the ground, but I could probably handle the carrying if I could pick them up from a standing position.