I am a wimp when there's a heat wave! But there's also a material to the rescue called linen. The linen I'm fond of is the Italian linen because it's lighter weight vs. Irish Linen that's heavier. The flow is graceful when you see a man or a woman wearing linen, reminds of hot days and old movie locations in the desert.
I would love it if more American men wore shoes without socks like this example. Actually the comfort is pretty good if you wear suede or rubber sole shoes.