Which layer of turnout gear keeps liquids and vapors, such as hot water or steam, from reaching the skin?

The moisture barrier is designed specifically to prevent liquids and vapors from penetrating the turnout gear and reaching the skin. This layer is critically important because it protects firefighters from potentially harmful substances, including hot water, steam, and hazardous materials, that they may encounter in various emergency situations. It allows for sweat to escape from the inside of the gear while preventing external moisture from getting in, thus ensuring the firefighter remains dry and safe.

While the outer shell provides some initial protection against heat and abrasion, and the thermal layer is focused on insulation from heat, the moisture barrier plays a distinct and vital role by acting as a shield against liquid infiltration. This feature is essential for maintaining firefighter safety and comfort during operations. Understanding the specific functions of each layer helps to appreciate how the turnout gear as a whole protects against the various risks faced during firefighting activities.