Gate 3 Airstreams Renewable Practice Test 2026 - Free Airstreams Renewable Practice Questions and Study Guide

Depth of burn is defined by how many skin layers are damaged. A burn that goes through the entire thickness of the skin is a full-thickness burn, which is a third-degree burn. It can extend into underlying tissues such as fat, muscle, or bone depending on how deep it is. First-degree burns affect only the outermost layer (epidermis) and are usually red and painful but blanch; second-degree burns involve the epidermis and part of the dermis and often blister; fourth-degree burns extend into deeper structures like muscles or bones. So the description given—affecting all skin layers and potentially touching underlying tissues—fits a third-degree burn.