The sauna's thermostat logs the temperature every minute and the door has a contact that logs every opening, because a sauna that is too hot or a person who is in it too long is a liability. The heater is isolated at half past nine. At about midnight the log shows the cabin climbing to ninety, holding for twenty minutes, the door opening once in and once out, and the cabin is warm to the hand at six.
I am the wet side supervisor, and the sauna is the part of it with the most paperwork.
How the sauna is logged.
The thermostat records the cabin temperature every minute. The door contact records every opening. The heater is on a timer during the day and is isolated at the breaker at close, by me, because a sauna heater is a fire risk, and the isolation is logged too.
An isolated heater is cold. The cabin falls to the building's temperature within an hour and stays there.
At about midnight, most nights, the cabin temperature climbs.
From twenty to ninety over about fifteen minutes, which is what the heater does from cold. It holds ninety for twenty minutes. The door log shows the door open at the start, for the time it takes a person to go in and sit, and open at the end, for the time it takes a person to come out.
Then the cabin cools, over an hour, to twenty.
The breaker is off. I have had my own padlock on it. The heater's element, which is where the heat comes from, is cold at midnight, by a thermocouple I have taped to it and logged. The cabin around a cold element climbs to ninety.
What has been checked.
The thermostat and its probe, replaced. The door contact, replaced. A second logger, mine, hung in the cabin, which reads ninety at midnight beside the thermostat's.
The cabin. It is a wooden box with a bench. I have been in it at midnight with the heater isolated and the element cold to my hand and the air at ninety degrees, by my logger, and by my skin, which is a thing you cannot argue with, and I have come out after two minutes because ninety degrees is ninety degrees whatever is making it.
The door. On the camera in the changing area, which sees the sauna door, the door opens at midnight, on its own, the width a person needs, and closes, and twenty minutes later opens and closes again, and nobody goes through it either time.
The session.
Twenty minutes at ninety is a session. It is the session the sign on the door recommends, and the heat curve inside it is not flat: it has the small drops of the door being cracked to let some heat out, the way a regular does, at the same points in each session, every night, for as long as the logs go back.
Somebody uses our sauna at midnight who knows how to use a sauna.
What is done about it.
The night session is on the log and the log goes to the safety file, and the safety file has a note from me that the thermostat records an anomalous temperature rise overnight with the heater isolated, and the insurer's inspector has read the note and asked whether the heater could be energised through a fault, and I showed him my padlock, and he wrote that the isolation was satisfactory.
What I do.
I supervise the wet side.
The one thing I have changed is the towel.
The sauna has a bench and people put a towel on it, and I used to leave the cabin clean and empty at close.
I leave a towel on the bench now, folded, a clean one from the stock, and in the morning it has been sat on. Not moved. Sat on, in the middle, with the crease pressed flat in the shape a person leaves, and it is damp, and it is warm, and the reason I started leaving it is that on the mornings before I did, the bench itself had that shape on it, in the wood, in sweat, and I had to explain the bench to a cleaner, and I could not.