Frostbite is a cold-related medical emergency. It refers to damage to tissue due to exposure to cold temperatures. Following are the stages of development of frostbite: Stage 1: Skin is irritated. This stage is associated with pain. Stage 2: Appearance of blisters Stage 3: Permanent damage to tissue. It involves all the layers of skin. Stage 4: Bone and tendon may freeze. Reference: https://www.emedicinehealth.com/frostbite/article_em.htm Image via: https://www.sciencenewsforstudents.org/article/scientists-say-frostbite