Guitars are sensitive to both heat and cold, so it is important to keep them in a cool, dry place. Extreme changes in temperature can cause the guitar's wood to warp or crack, and the finish can also be damaged. Cold environments can also dry out the wood, which can make the guitar more susceptible to damage.
The ideal temperature for storing a guitar is between 65 and 75 degrees Fahrenheit (18 and 24 degrees Celsius). If you live in a climate with extreme temperatures, it is a good idea to keep your guitar in a case when you are not playing it. You should also avoid leaving your guitar in direct sunlight or in a humid environment.