Can bees use their body heat to kill enemies in the nest?

Yes. This technique is used by Japanese honey bees on their predator the giant hornet. When the hornet enters a nest, the bees swarm over it and vibrate violently to produce heat. The heat they produce is about 2 degrees more than what the hornet can tolerate. They can only do this 1 hornet at a time and so far no other specie is known to do this yet.