You spend a third of your life in them, shedding skin and sweating. Weekly is the consensus across dermatology and textile guidance alike.
The short answer
weekly
When to wash sooner
Wash it now if
- a week has passed
- hot weather or night sweats
- illness, allergies or a pet in the bed
What to do between washes
Air the bed each morning before making it. Pulling the covers up immediately traps the moisture in.
How to wash them
60°C for cotton if anyone has allergies, otherwise 40°C is enough for cleanliness.