The place where i live in actually more pleasant in summer then other places, though it still very hot(close to 100 degrees currently). I sweat a lot too and my problem is mainly with the hairline. Am currently using something called sigma bond which i picked up here and the max attachment i get is one day. As far as tapes are concerned, ST 30 was easily the best followed by Supertape.Will let you know next week about the new tapes at Debbie's splitend-Low residue and Pro 2000 as they shd reach me anytime. I have read great things about these tapes.
Anyway, tape attachment lasts me for about 5 days and as i said hairline has to be touched up every day.