The concerns when using parts at low temperatures beyond the temperature range are the "rate of change of the capacitance," "reliability," and the "temperature cycle resistance."
Regarding the rate of change of the capacitance, the temperature range of the X5R characteristic products is from -55 to 85 ºC, for example. Although the rate of change standard of the capacitance in this temperature range is "+/-15%" for the X5R characteristic, there is concern that the rate of change of the capacitance may not satisfy the standard by using the part outside of the temperature range.
Regarding reliability, since ceramic capacitors have temperature acceleration, it tends to become more severe at high temperatures.
There is no concern of the reliability deteriorating by using the parts at low temperatures beyond the operating temperature range; however, condensation should be prevented.
The heat resistance cycle deteriorates as the temperature range expands; therefore, be aware when using the parts in environments where the temperature fluctuates repeatedly between the maximum and minimum operating temperatures.
(Please understand that the use of parts outside of the operating temperature range are not applicable for guarantee, for the X5R characteristics.)