Why a musician must return a stringed instrument if it's temperature change ?

A musician must return a stringed instrument if its temperature changes because temperature fluctuations can cause the wood of the instrument to expand or contract, which can affect the tuning and overall sound quality of the instrument. Additionally, extreme temperature changes can also cause damage to the instrument, such as cracking or warping. By returning the instrument to its proper temperature, the musician can ensure that it remains in good condition and continues to produce the desired sound.