A midlayer is the garment worn between your base layer and outer shell, providing essential insulation and helping regulate body temperature. Good midlayers trap warmth, wick moisture, and are breathable, making them crucial for comfort during snowsports, hiking, or everyday winter wear. 

Common midlayer options include fleeces, hoodies, sweatshirts, synthetic insulated jackets, and lightweight down jackets. Fleeces and synthetic options offer breathability and quick drying, while down provides maximum warmth for very cold, dry conditions. Choose based on activity level and weather. 

Fleece hoodies excel in warmth, moisture-wicking, and lightweight comfort - ideal for active outdoor use. Sweatshirts, usually cotton or cotton-blend, are cosy and versatile for casual wear but less insulating and moisture-wicking than fleece. Hoodies add head protection and often feature pockets for extra functionality. 

A midlayer should fit snugly over your base layer but not restrict movement or feel bulky under an outer shell. Look for enough length to cover your lower back, sleeves that reach your wrists, and a cut that allows full arm movement. Proper fit ensures warmth and layering efficiency. 

Fleece (polyester) is lightweight, warm, and quick-drying - great for most conditions. Synthetic insulation retains warmth even when wet, while down is best for dry, cold climates due to its superior warmth-to-weight ratio. Avoid cotton, as it retains moisture and can make you cold. 

Yes, in dry, mild weather, many midlayers like fleeces, hoodies, or insulated jackets can double as outer layers. For harsher or wet conditions, use them beneath a waterproof shell for added protection and warmth.