What causes skin to do this?

Okay, my sister showed me something cool that you can do with ice and salt. You first wet your skin and cover the wet area with salt. Then, you press down on it with a cube of ice for about a minute. It stings a litle bit, but when you take the ice off,...

the area is cold, hard, and white. After about 20 seconds it turns softer and red and puffy. I did it to myself for several minutes and it turned into a welt.

Does anyone know what causes skin to react that way with salt and ice?

lol whats wrong with you? you guys have way too much time on your hands.

Haha, I know. We were really bored. It's not like we were doing any self inflicting injuries, we were just messing around until it started causing welts. I'm just curious as to why that happened. lol.

what you have created with the salt and the ice cube..is frost bite actually...
and its considered a form of self harm..and if you dont treat those areas properly..it can scar because frostbite is essentially dead flesh.

nl83 is right
its very dangerouse to do that
and if you keep it up you could actually kill the skin there
and that will get infected and start to go black, and then kill the skin around it
its defenetly not "cool"

Ya, we're definately not doing that again. It was cool until the marks didn't go away. They starting to fade so I don't think the skin is dead.