Maybe Facebook would be good to increase his sponsorship funds? Local business where he is from and went to High School might also be interested if it goes in the local paper that they are helping out, we can read a lot of these stories in our local weekly.
Although Nepal isn't expensive compared to other countries, he must make sure he has enough to cover his expenses - we went on a treck some time ago organised by a local doctor in Ladakh and a girl came with us who was sponsored . She didn't pay the guide , ate on other people's fees, basically had a free ride as she signed up and then could only pay for her flights....
It is so good of him to go there, a lovely country with beautiful and kind people. It is well equipped to deal with Westerners as it has lots of tourists coming through. Does he want to help out in the Capital or in the country?
He knows that the summer is the worst time for the weather ? Maybe wait until October/November when the Monsoon is over? And he will have more time to find the funds? He will also need some vaccinations - it might be a bit late for those already to kick in for the summer!