A MIPS ski helmet is a specialized type of ski helmet that features a built-in MIPS (Multi-directional Impact Protection System) liner. This additional layer of protection is designed to help reduce the risk of head injuries in the event of a fall or collision. MIPS ski helmets are becoming increasingly popular among skiers and snowboarders, as they offer an extra level of safety on the slopes. While they may cost slightly more than traditional ski helmets, many people feel that the added protection is worth the investment.