What if you only do it for a minute? Does it go away very fast? I will never do this again! It left a mark on my cousin and I. :( Do you have to go to the doctor?

I answered your question when you piggybacked on this thread:

https://www.askmehelpdesk.com/medications/did-salt-ice-challenge-how-can-get-rid-burn-without-doctor-729666.html

It's a burn. Yes, it needs medical attention, and no, it won't go away fast.

Going away depends on how bad and how soon you get proper medical attention.

I have some scars from 50 year ago on my hands that will never go away,

I have two marks ; Two hands, it's super annoying I am worst than you

I cover it with foundation. Kindof helpful though..

Just remember, every time you look at it you can ponder this decision and contemplate the results of saying yes to doing stupid things. It isn't jumping off a cliff but close enough.