The Qi-Shield, Qi-Home Cell and Qi-Max Cell can be exposed to temperatures down to 5° F. It is recommended that Qi-Technologies devices be kept in temperatures between 41° F and 104° F. Falling below or exceeding this temperature range can lead to damage and thus impair the functionality. Strong fluctuations in humidity should also be avoided as both the lid and the base are made of wood, and humidity changes can cause cracks in the wood which will affect the aesthetic of the device (but will not affect the functionality).