The watch I bought last time is always foggy when it is cold. what can I do?

This is because the air in the watch contains moisture. High-end watch manufacturers will blow dry the air inside the watch before installing the back cover. There are two possibilities. First, the waterproof apron of the watch is aging and its waterproof ability is reduced. The air in the second-hand watch will condense when it is cold. There are two simple ways to solve this problem. Put the watch and the new desiccant in a sealed bottle or plastic bag for two days. Second, put the watch under the ordinary light bulb of a lighted desk lamp and heat it for more than seven or eight hours. There are two possibilities. First, the waterproof apron of the watch is aging and its waterproof ability is reduced. The air in the second-hand watch will condense when it is cold. There are two simple ways to solve this problem. Put the watch and the new desiccant in a sealed bottle or plastic bag for two days. Second, put the watch under the ordinary light bulb of a lighted desk lamp and heat it for more than seven or eight hours. If not, send it to maintenance, inspection and replacement of waterproof apron.