Desert Tortoise w/ Possible RI. Advice Needed!

So my neighbors have a desert tortoise who's 55, and they asked me to watching him for a day while they were out of town. I noticed that there is some clear fluid coming out of his nose when he exhales. As I am not very experienced with tortoises I googled it and saw that one of the signs of an RI is fluid coming out of the nose. However, he breathing seems fine and is not labored and he definitely had quite an appetite when I fed him. I am guessing the nose running is not normal and I will definitely let the owners know ASAP but is there anything I can do in the mean time? Can anyone with experience confirm whether or not this sounds like an RI?

Right now he is outside during the day, and inside at night.

I'm sorry, I wish I could be of help, but I have zero experience with tortoises. I don't know what state you're in...when I lived in California, there was a fairly active
turtle & tortoise rescue group...have you tried to search for such a group wherever you are? I do recall that tortoises often have a contagious RI like this, & should
never be put back in the wild (where it can spread & make the healthy wild populations sick too), but I don't know what if anything you can or should do for it as far
as care.