Well, the Urban Dictionary says,
"1. ice burn
12 thumbs down
spraying an aerosol on yourself, the coldness burns it
me n dave were playin wit lynx last week, he gave me an ice burn"
I, being a now-country bumpkin would say it is frostbite as it burns and stings when the affected flesh starts to thaw. Even getting a bit of flesh very cold into numb will sting as it thaws out. You have freezer burn right, as most of us 'Murricans can tell you.
A real geek explanation is here:
http://www.ntnu.no/gemini/1993-dec/24.html