Calling in from the asphalt desert - Phoenix metro. i concur with all these ladies about water and liquid. I actually run electrolytes in my camelbak - the stuff from alacer. It's 100% minerals, so it doesnt' lead towards nasties in the drinking supply. My water bottles have drinks with energy suppliments as well as electrolytes. I always have extra packets to refill at whatever gas station is most convienent. Of course, if I'm planning on a ride less than 20 miles, I won't bring both water bottles and camelbak.

As you acclimate in the beginning of summer, take it easy on yourself. allow your speeds to drop as you body aclimates to the heat. I'd say the worst I've probably ridden in was 115-117 range. I don't remember exactly what it was. Honestly, once I acclimate to 105, all the upper temps don't bother me as much. It's the sun that kills me. Watch your UV indexes. I think those might be a bigger indicator of when my speed has to drop. UV of 10 is nasty nasty. I love it when we get humidity, as it brings clouds with it, which block the sun. Without the sun, any temperature is bearable.(biking, that is!) 110 - or even 100! - inside an enclosed building with no airflow sounds insane!

Take it easy when you get back inside. drink more water then.

Oh, I don't know about you gals, but I could literally ride 30-50 miles in any direction and not find desert. It'll get worse with time as my company designs master plan communities that go waay out into the boonies. Thus there is a gas station commonly found at every few miles - unless you have really bad luck/planning skills. They all let you use their soda machines to get free ice and free cold water. it's great to refill everything and keeps it cold. (since I'm typically looking at 60-100miles on any given saturday, this is a necessity)