Since the portable device such as smartphones and tablets rely on batteries to operate, care should be taken to preserve the life of a battery.
You should operate your iPad at room temperature recommended by Apple 22degrees Celsius.
iPad Temperate Zone. Your iPad is designed to work in conditions ranging from 32° to 95° F (0° to 35° C). But keeping your iPad as near room temperature as possible (72° F or 22° C) is ideal.
See Apple website for more information.