SuLiao Sauna Sand Timer Hourglass 15 Minute, Rotating Wood, Black Sand

Phones and smartwatches do not belong in a hot sauna, and most are not built for that heat anyway. The traditional answer is a sand timer on the wall. This one runs 15 minutes, with marks at 5, 10 and 15 so a shorter round is easy to read off. The glass tube sits in a wooden frame that rotates on its wall bracket – turn it when you sit down, and again for the next round.

The maker gives the accuracy as ±10%, so treat it as a guide, not a stopwatch. That is the right attitude to sauna time in any case: your body is the real timer, and you leave when you have had enough, whatever the sand says.

Tip: Mount it at seated eye level on a side wall, well away from the heater, so you can read it from the bench without moving.