MIDWEIGHT BASE LAYER - Our base layers are designed for warmth, performance (including but not limited to breathability and moisture management), and wearable comfort. The adventure is yours, we'll keep you warm and comfortable. RELAXED FIT - Designed with a looser fit that lies gently on the skin without binding. Generally, there is little to no stretch in the fabric. Therefore the silhouette is designed to accommodate movement. Often used in lifestyle wear, as well as for a base layer. WARMTH FACTOR 7/10- Ranked from Mild to Hot, the Warmth Factor Thermometer tells you how warm each of our products is. Warmth Factors 6, 7, and 8 are considered Midweight and are very popular for most cold-weather activities. MOISTURE TRANSFER FIBERS - An essential feature in all our products, Hot Chillys exclusive moisture transfer fibers (MTF) move moisture away from your body by employing hydrophobic yarns to wick away perspiration, thereby keeping you dry and comfortable. MECHANICAL STRETCH - Engineered to stretch and move with you, providing all over fit, warmth and expedited moisture movement.