Je was best je haren voor het slapengaan, zodat je de pollen niet in je bed brengt.

Original review summary

The review says washing your hair before bed removes pollen left in it during the day, which may otherwise reach your pillow and face and trigger nighttime sneezing and a runny nose. It notes that the effect of hair-washing alone has not been studied, though the measure appears in several guidelines as part of practical advice for hay fever.[S1]