This can't be normal

So, now that it's warm out, I've mostly stopped wearing shoes. This is because shoes make my feet too hot and they're uncomfortable. Unfortunately, I have problems when I switch from shoes to flip-flops. The soles of my feet get hard fairly quickly--probably because I walk around so much--and if I'm not used to walking without shoes on, eventually the heel starts to crack. Right now, I've got about a half-inch split on my left heel, which as you can imagine, is uncomfortable. Every time I take a step, it tries to split a little wider--as do all the other mini-cracks that haven't begun to hurt yet--so the only way for it to heal is if I stop walking, but I'll have the same problem as soon as I start walking again--not to mention that I won't be able to get anywhere. This happens to me every year, and I know it will go away after a while, but it is annoying as it's happening.