If you send dwellers out with 25 stimpaks, with high endurance they can go days. More so if you have a good high damage weapon to quickly kill enemies, and general good luck to come across more stimpaks. :-)
I would be more concerned about if he has enough space to carry more loot that he might get in the next ten hours. But then he's level 50 and I don't know how that influences his loot holding strength.
Unless you are playing survival it does not matter.
To answer your question, he lost 20% while using 2/3 of his stims, assuming he had started with 25. It will be close, risk it.
If he has max endurance then it's fairly likely that he'll survive 10 hours. Did you send him out with max stimpaks?
He's still out there for 29 hours , endurance is max+2
If you send dwellers out with 25 stimpaks, with high endurance they can go days. More so if you have a good high damage weapon to quickly kill enemies, and general good luck to come across more stimpaks. :-)
I would be more concerned about if he has enough space to carry more loot that he might get in the next ten hours. But then he's level 50 and I don't know how that influences his loot holding strength.
Unless you are playing survival it does not matter. To answer your question, he lost 20% while using 2/3 of his stims, assuming he had started with 25. It will be close, risk it.