Heat and calve cramps

The last several months I've been plagued with calve cramps during my runs. After my HIM, I backed off the milage from 40 miles/week to 28 miles a week, thinking maybe I was overdoing. The cramping in my calves is really hit or miss, sometimes I get them bad, sometimes a little, sometimes none. There is no pattern. They've happened when I 've had a 12 mile week and a 50 mile week. If they are bad, I stop each mile and pull them out and after about 3 miles or so, they go away and I'm fine for whatever distance I'm doing.

But looking through my training log(which I do on paper cuz I'm like that) I noticed that I am cramping on days when its really hot. and not having problems on cool days.

Aside from running later in the eve so its cooler, anything else folks have found that helps this?

I really suck at hydration and am really trying to improve this.

Thanks!
Suzanne