hmmm... well when you get really cold(hypothermia) temp you arne't numb you actually feel like thousands of needles stabbing you. And burning I would assume would hurt like a mother fucker. I mean your cooking alive, and every heat, and pain receptor in your body is going to hurt.
But which would you die of faster. I would say burning alive because your body temp can only get to about 110F before your internal organes start to melt(literally)
but with ice you would be in more pain because it takes longer to freeze to death. Because your core body temp has to get to like 50F And that you take longer(depending if your wearing cloths or not)
So I would like to die from freezing to death. I would just swim under the ice and suffocate to die faster.
Id rather die of old age or something really fast.
Joy, another oxymoron phrase, (but not the user who posted it) =D
You said freeze to death, but you didn't say what temperature. I'd go with the Zero Kelvin temperature, where every single atom will stop and disintegrate immediately upon contact. Loophole =)