The Walking dead/What if?

[Danny]

It wouldn't happen though. At least, not in the sense of dead bodies coming back to life. A body wouldn't survive any kind of heat due to the rate it'd decay under the sun, any more than it'd survive the cold - we're something like 70% water, without our bodies creating heat surely we'd just freeze.
In addition, they lumber around so slowly that the chances of catching any living thing and biting a chunk out of it are pretty slim.

"Zombies" à la 28 Days Later or I Am Legend (airborne virus) that's another story...