Just checked its Raws. Unfortunately, even though Alphapolis says 連載中 (Ongoing) and there seems to be a survey on Alphapolis, I am inclined to agree that it's done because it says that it updates on the last Monday of each month, and this chapter was released on Feb. 24th.
The only proper restriction for sauna use is - you have to be able to walk out on your own. (As long as you can easily decide that you need to go out and chill a bit, and act upon it, all is fine.)