Underneath a snow suit, it's important to dress your child in layers to ensure optimal warmth and comfort. Start with a moisture-wicking base layer, such as thermal underwear or a long-sleeved shirt, to keep sweat away from the skin. Add a fleece or wool mid-layer for insulation, which helps trap heat inside the snow suit for kids. Make sure the layers are snug but not too tight, allowing your child to move freely while staying warm. For snow suits for boys and girls, it’s also a good idea to have warm socks, gloves, and a hat, which provide extra protection from the cold.