Seasonal slow drifts are less harmful to structures and objects than abrupt changes. However, if you are in a wet or dry climate, it may not be possible to maintain the ideal RH level. If you cannot achieve even these levels, achieve a reasonable level that does not fluctuate. Materials last longer at cooler temperatures. A rapid change in temperature, if the relative humidity is constant, may have damaging effects on stressed metals, stone, films, plastics or wax, materials from which many modern collections are made.
High temperatures increase deterioration reaction rates and melt heat-susceptible materials.
Store inherently unstable materials, like plastics and rubber, in cool temperatures and lower RH levels to decrease the rate at which they naturally deteriorate. Waxes and plastics are damaged by freezing, so should be kept cool, but not frozen.