I've come around on summer's heat nonsense. Once it's your job to endure the heat while hiking through the frickin backcountry, not much about plain old summer phases you.
Not that I'm immune from the heat – I've started sweating the minute I step outside in the mornings. I just don't give the heat much mind.
The one thing I can't get past with summer is the damn mosquitos. I think I'd rather get punched in the throat once by Rocky Balboa than endure a lifetime of insatiable itchiness. Mosquitos thrive in hell, if it exists.