So, which altitudes are bad? I live at around 4200' and I think that's a good altitude, but some may disagree. I think low altitudes are the bad ones. By what mechanism does the heat change the altitude? I know that heat can increase the altitude of a balloon, but I didn't know it worked on landscapes as well. Bill in Willcox _____ From: az-geocaching-bounces@listserv.azgeocaching.com [mailto:az-geocaching-bounces@listserv.azgeocaching.com] On Behalf Of Gale Sent: Thursday, May 19, 2005 1:49 PM The heat does tend to produce bad altitudes in the residents of the Phoenix area. I suspect it will be worse with the high gas prices.