I have been washing mine on 40° - following the care label but it seems from reading another thread that some wash theirs at 60° to get rid of germs.
Once I read that I'm worried that the germs are still there!
My washing machine only has 2 settings at 60°, one is a cotton cycle and the other is a synthetic cycle both are quite long at approx 2 hours.
How do you wash yours? :)