1/ Daily up-keep
Looking after your helmet is child's play.At the end of your day on the ski slopes, remember to always dry your ski helmet well before putting it into its protective cover.
If it is still damp, even slightly, the moisture will not escape and therefore prevent your helmet from drying which could affect your comfort and lead to it smelling badly.
Also take care to avoid shocks when returning back to your accommodation and at all times to maintain the effectiveness of your helmet.