Okay, we’ve all seen the scene so many times we don’t think about it. But think about it.
Luke is hanging upside down from the ceiling of the wampa’s cave like a human stalactite, his feet encased in ice. So first of all, how’d he get there? Sure, the wampa put him there (for reasons that are less than entirely clear), but how?
To encase someone’s feet in ice, you first have to melt the ice, then stick the guy’s feet in, then wait for the ice to refreeze. How did the technologically-challenged wampa melt the ice?
But wait, there’s more. This ice is on the ceiling. If you melt it, it, y’know, falls down. So how did the wampa keep the water from draining off as he held Luke’s feet in it?
Answer: that must not be how the wampa did it. Well then, how did he do it?
And finally, after Luke cuts himself free with his lightsabre (with a single stroke – what “shape” would that stroke have to be, I wonder?) and jumps down, why aren’t his feet still encased in chunks of ice?
Possible answer: the lightsabre is so hot it instantly melted the rest of the ice. But that doesn’t seem right. Whatever directly touches a lightsabre’s blade gets pretty hot, yes. But we’ve seen that the blade can be an inch or two away from someone’s skin without causing burns. So how could one quick slash with the blade be enough to melt, instantaneously, such a large amount of ice?