Casio's Sadokei watch can withstand temperatures of up to 100 degrees celcius, reports The Yomiuri Shimbun, but they don't want you to swim in boiling water. It's for the sauna. The battery is heat-resistant and encapsulated within a water-resistant resin, and it comes with a stretchy band that looks like an old-timey phone cord. It comes in black and white; "Sauna mode" sets it to lock the small hand and revolve the big hand in 12 minutes, perfect for a quick steam bath.

Casio crowdfunded the launch last year and sold out 2,200 watches in nine minutes.
Previously:
• Casio watch ring looks wonderfully ridiculous, but is sadly non-functional
• New Casio desk clock is a giant version of an old wristwatch
• Casio's 1972 calculator is now a 2024 wristwatch
• Retro Casio watch has a few smart features