FWIW....The Honig's K2 chest protector is a good option for those of you worrying about the heat.
I live in Phoenix, so I think that I know about games in the heat. I switched from the traditional full length protector to the K2 last year and absolutely love it. It is lighter and easier to wear than the old one. It provides protection for the collar bone area and the sternum. I have plenty of "natural" padding above the waist. Several of my collegues here in Phoenix wear the K2.
(Now I just need to contact Honig's for my kickback)