Your watch is a precision measuring instrument. Treat it carefully, and
it will serve you well. Avoid undue shocks (such as dropping on hard
surfaces). The normal shocks caused by sports like tennis or golf
present no threat.
Perspiration: You should aim to protect your watch from heavy perspiration. Please remember to wipe it dry as soon as possible.
Temperature Extremes: Quartz watches are much less affected by extremes of temperature than mechanical watches, and are designed to keep good time if worn on the wrist for eight hours a day with ambient temperatures between -10°C and +35°C. If removed completely from the wrist, your watch may lose time during the winter, but will return to normal accuracy as soon as you start wearing it again.
If your watch is stored at temperatures outside the normal range (as low as -10°C or as high as +60°C) the electronic components may cease to function normally.
The response time of liquid crystals used in the displays on digital watches at temperatures below freezing is slow, and they tend to look very dark at high temperatures, but normal performance returns at normal temperatures.
Battery life can be significantly reduced at high temperatures (above 40°C), and battery fluid may even leak out.
Chemicals: Chemical substances, gases, mercury, etc., may change the color of cases, bracelets and straps. Mercury (for instance, from a broken thermometer) can cause particularly unsightly grey discoloration of gold plating.