1995 Nissan Pathfinder loses power once it gets warm?

yes your fuel pump, im guessing its electric fed, so the reason it is only doing it when it is warm is because that's when the truck is using the most fuel, since its using more fuel the pump cant keep up that's why its shutting off, think about it like this lower RPM's less fuel needed to run= cold engine: higher RPM's more fuel needed to keep engine running = warm engine: worse case scenario engine is going bad but then you'll have to do a compression test but your engine shouldn't be cutting off, same with catalytic converter, last thing to check is if your check engine light comes on and turns off, if that's the case it could also be an 02 sensor, soo all on all its either fuel pump or o2 sensor, hope i wasnt too confusing

This sounds like the classic plugged up catalytic convertor. Many city driven exclusively cars/trucks suffer this fate every 5-10 years from not having sufficient exhaust flow or velocity to get the cat convertor hot enough to burn off the oil and gasoline residues that build up and it creates sufficient back pressure on the engine to stall it after the engine has warmed up or run for a little while.

AN easy test is to pull one of the O2 sensors after it stalls (red hot so watch out) and then crank the engine and if it continues to run (exhaust will escape through the hole where the O2 sensor was) then you will know it's the cat convertor.

Good Luck!

Sounds like the fuel pump. I assume he or she checked fuel pressure and it didn't meet specifications.

"Test" the vehicle when its cold by revving it hard and high, see if you can make the problem happen ( the reason for this test is to see if the fuel pressure is the actual factor ) if it doesn't happen when you try, it could be a vacuum or idle sensor issue.

it is clearly your battier