The Happy Ring has been designed to withstand just about anything you throw at it, with an ideal operating temperature ranging from 14°F – 129°F (-10°C – 54°C). With that said, we do not recommend wearing the Happy Ring in extreme environments for prolonged periods, such as hot tubs, saunas, ice baths, and cryotherapy tanks, as those may likely exceed those thresholds and lead to inaccurate readings or sensor/battery damage.