Temperature and Outdoor Gigs

[journeybear]

So I take it you're going to be "Brian" in this context? I guess that makes sense, as Mr. Jones was the multi-instrumentalist in the band. If any original member were to have picked up mandolin, it would have been he. Perhaps they could use you on sitar for a song or two?

[Sevelos]

Whether these mandolins will be damaged from the heat, I cannot say. Regarding playability however - I had lots of problems performing outside during the summer, here in Israel.
When it is hot and humid, my left hand starts sticking to the neck and it becomes very difficult to change positions on the neck. This happens especially with the Greek bouzouki, which has a long neck, but also on my A8 mandolin.
I have used baby powder for a couple of years, but I don't recommend it - initially it helps, but after playing for an hour or so with baby powder, the left-hand fingers start sticking to the strings and making it hard to play. Besides, baby powder leaves a lot of ... baby powder on the mandolin.
My current solution which works very well, is "Dr. Ducks Ax Wax", which is a kind of mineral oil (with a funny name) for musical instruments. Before every performance, I use a towel to generously smear this oil on the neck and the strings. Works well even in the hottest weather.