, a sleeping pad
is a simple device often used in conjunction with a sleeping bag
. Its purpose is to provide padding and heat
insulation. The ground may become quite cold at night
, and is often covered with sticks, small rockss
, and other objects that may make sleep
difficult. A sleeping bag does not provide adequate protection against either hazard, but a sleeping pad does.
The simplest sleeping pads are sheets of firm plastic foam, stored in a rolled-up configuration. More expensive (also heavier) models are designed with interconnected air cells that may be compressed for maximum compactness, or inflated through a valve for maximum padding (air-bed, air-mattress).