The purpose of this research is to investigate the parameters affecting the insulation layers of sleeping bags on its thermal properties in cold, windy, and wet weather conditions. Thermal resistance, compressibility, and moisture transfer were measured under cold conditions (dry, wet, and windy). The results showed that among the filler materials, hollow polyester fibers have the best thermal insulation property (equivalent to 0.935 Clo). Also, increasing the weight per unit area of the sleeping bag layers has a positive effect on the thermal resistance. The sleeping bag containing hollow polyester fibers with a weight per unit area of 100 g/m2 has the best compressibility, and as the weight per unit area increases, the compressibility decreases. The moisture absorption test results showed that increasing the thickness increases the time required for the concentration distribution to reach equilibrium. Statistical analysis showed a significant difference (p < 0.05) between the performance of hollow fibers and natural fibers under wet conditions. The thermal camera results showed that over time, as the moisture concentration in the outer layer decreases, the temperature of cold spots in the samples decreases. For all filler fibers at ambient temperature, the presence of wind causes the moisture of the fibers to dry faster, which occurs more rapidly for hollow polyester fibers due to their low moisture absorption. The shortest drying time for hollow polyester with a unit weight of 100 g/m2 is 0.15 minutes, and the longest drying time for chicken feathers with a unit weight of 300 g/m2 is 51 minutes. In cold conditions, the presence of wind causes a sharp drop in temperature; however, the temperature drop for natural wool fiber is much greater than for synthetic polyester fiber.