"The Week of Paul" ends with an explanation about something I'll never get ... his new-found affinity for saunas.
A friend invited me to the Russian in Manhattan and I took him up on it.
The bath house has several different versions of saunas: a blazing hot Russian one, a Turkish one, a red wood Swedish-style one, a and an intense aromatherapy room.
The basic premise is that you sit in one of these saunas until you're about to pass out from the heat, then you plunge into the ice cold pool at the facility that's kept just above freezing.
Going from overheated to near hypothermia shocks the system and leads to a sort of euphoria and an intense feeling of relaxation.
After doing this for a while, we put our silly-looking robes on and went up to the cafeteria where we ate Russian food (I had the herring) and drank giant Baltika beers. This got me feeling very good and we went back into the saunas for another hour or so.
I witnessed the strange Russian ritual in the unbearably hot Russian sauna (I think it's around 135 degrees in there) where a big brawny 'masseuse' would dip a bunch of oak leaves in a bucket of and beat a person with them while they laid down on the side of the sauna. I had to pass on that- I felt it was sadomasochistic enough to sit in this sauna where you need to pour buckets of cold water on your head just to keep from passing out.
After a couple more sessions, we retired once again upstairs where we had another and relaxed on the rooftop terrace with the old, shirtless Russian men.
I was so relaxed, I nearly passed out on the subway ride home and came to an understanding why so many cultures are into this.
He doesn't write about saunas at Presidents by the Book, but you should visit it anyway.