My solution has been to wear a t-shirt tucked in and a polo untucked with my HK p30 40 cal clipped inside my belt on the right side of my back.
It is a tad heavy to wear with shorts that don't have a belt, but I miss it when I don't have it.
Looking at buying one of these. Diamondback Site
and a pocket holster to reduce printing.
They feel GREAT! And have heard nothing but good things about them.
x3 on the AC. Here in TN lately it have been in the 90's and humid. You feel like you took a shower when you are out for more than a minute.