The 120 degree F water provides an oasis of relief for the trail weary.
Nude use is permitted as long as no one complains.
A strict limit of 20 visitors per day is enforced, so be sure to make reservations before going. Midweek is best. Go east on I-90 from Seattle to the Snoqualmie Pass and look for the signs to the Cascade Crest trails. We were in a 4xSuburban and even driving carefully, managed to get into a soft shoulder and get stuck. That was about mile 16 meaning we still had 6 more miles to travel to the parking area.