What should the inner layer of clothing include?

The inner layer of clothing is essential for regulating body temperature and managing moisture next to the skin. It should be designed to wick moisture away from the body while providing insulation. Basic underwear and long underwear are ideal for this purpose because they are specifically made from materials that keep you dry by absorbing sweat away from your skin. They trap heat, helping retain warmth in cold environments, which is crucial during search and rescue operations in varied weather conditions.

In contrast, heavy jackets are suited for the outer layer to protect against wind and rain but do not serve the moisture-wicking function necessary for the inner layer. A t-shirt alone may not provide adequate warmth or moisture management under more challenging conditions. Lastly, only wearing thermal tops lacks the comprehensive coverage that both basic and long underwear provide for optimal layering and thermal regulation. Therefore, having both basic underwear and long underwear is the most effective choice for the inner layer in achieving comfort and performance during outdoor activities.