Should be fine - see operating temperature notes below. The watchas to be able to withstand a certain amount of temaerature/himidity fluctuation.
Operating temperature Apple Watch is designed to work best in ambient temperatures between 32° and 95° F (0° and 35° C) and be stored in temperatures between -4° and 113° F (-20° and 45° C). Apple Watch can be damaged and battery life shortened if stored or operated outside of these temperature ranges. Avoid exposing Apple Watch to dramatic changes in temperature or humidity. If the interior temperature of Apple Watch exceeds normal operating temperatures (for example, in a hot car or in direct sunlight for extended periods of time), you may experience the following as it attempts to regulate its temperature:
- Charging may slow or stop.
- The display may dim.
- A temperature warning screen may appear.
- Some data transfer may be paused or delayed.
- Some apps may close.