Trust me, you do not want that. It'd get messy really fast.

But if you want to test me, I'm game. One week, provided you can bust it using cold.

[Well, Jack asked for it. Tony can devote some of his time to making a cold-resistant collar. And who's to say the technique won't come in handy later? He's sure that this is an appropriate use of his time and knowledge. No one is going to convince him otherwise, now.

Plus, he can say he beat the spirit of Winter later.]