The heads of golf clubs are held to the shafts using adhesives. As the temperature changes the shaft, adhesive, and head materials undergo shrinkage or expansion. (This is dependent on the clubs get hot or cold and the individual club component materials and adhesives used). Over time and repeated seasons of thaw and freeze cycles, the bond between the head and shaft can weaken or become compromised. This can result in the head separating from the shaft(may even lose the head), twisting of the head, and also potentially grip deterioration/hardening/cracking. Storing your clubs in a climate controlled environment will help minimize this. Since golf clubs are relatively expensive it is important to care for your clubs so they are ready to go when you are!
Important Tip – Leaving your clubs in your vehicle during hot days can also adversely affect the adhesive and your grips.