You're talking "hot foot" as in temperature, right? Not "hot foot" as the pain caused by too-tight shoes or ill-positioned cleats.

In any case, lots of folks report success with Keen sandals for riding in hot temperatures (they have plenty of fans riding in the winter, too -- people just wear heavy socks; they're good for winter because they dry fast after they get wet).

As for "hot foot," the pain caused by too-tight shoes, the answers are:
- wear your shoes looser
- position cleat to the rear, or get a good fitting
- switch from spd shoes to something with a broader platform
- super stiff soles