My son has blisters all over his knee after using an ice pack. looks like a burn. should he see a dr?

Ice burn: Ice can cause as much or more damage than heat. When an ice burn blisters, it indicates there is a burn that extends through a skin layer. You get him (his knee) into warm water between 104 and 106 degrees and observe, the area should begin to pink up, feel numb and tingling and then regain sensation. If this does not happen, he needs immediate medical attention.