In June, I packed my sneakers, sport sandals, and my Crocs. Never wore the sport sandals, switched off day and night with the sneakers and Crocs. Found I liked the Crocs best...so when I went in August with just my dd, I brought only my Crocs and sneakers. But, wore only the Crocs. So...in Nov/Dec brought only the Crocs. My feet were very happy.
I normally wear a 9. In those styles that are S, M, L, I am happy with a M, in those that offer actual sizing, it's a 9 for me. I found that I haven't had to 'break them in' at all. And no, they don't melt on the hot pavement. Believe me...if mine didn't melt in June and August, no ones are going to melt....well, unless you stick 'em in the dryer for 30 minutes!!