There's a well preserved Turkish bathhouse in the Old City of Nablus, Hammam esh-Shifa. It was built in 1624 by the Tuqan family, who came to wealth through their soap production. It retains most of its original features and is a a relaxing way to spend some time, any time of the year.
The bathhouses are usually open daily from 08:00-24:00 for men, except on Tuesdays and Sundays when they’re reserved for women 08:00-17:00.
You can get a scrub and a massage for a reasonable price.