We have been seeing a lot of guitars, violins, violas, cellos, double basses, and ukuleles coming in for adjustments lately due to action problems, buzzing strings and warping necks. These issues are mostly due to humidity control and changing temperatures. A lack of humidity in the air due to changing temperatures, not using an instrument humidifier, changes in altitude and improper instrument storage where temperatures fluctuate can cause these problems to occur. These instruments are made of wood which expands and contracts with temperature and humidity changes. The wood expanding or contracting can cause action problems, or even bow or warp the neck of a string instrument. To prevent this from happening to your instrument keep it humidified with an instrument humidifier and be careful where you store it. Wooden instruments should never be stored close to areas where extreme temperature fluctuations can occur. For example, by a heating/cooling vent, radiator, radiant heat, stove, windows or doors. If you detect a change in your instrument's handling or notice warping, bring it in to an experienced luthier for immediate attention.