Back home, use a damp cloth to remove anything that has stuck to the mat such as dirt, insect repellent, or sunscreen. If left on for longer periods, these can cause damage to the material, particularly if chemicals such as DEET are in insect repellent. For stubborn stains, use biodegradable soap. Once a season, completely clean the sleeping mat to remove body sweat and dirt, as they can transfer to a sleeping bag and compromise performance. Follow the manufacturer’s instructions for washing. When cleaning inflatable sleeping mats, take care to ensure that the valve is closed; drying the inside is tricky and it should not need cleaning.
After cleaning, dry the sleeping mat thoroughly (but avoid prolonged periods of direct sunlight), and open the valve. Take care to dry both the interior and exterior of the sleeping mat. Interior moisture can lead to mould and degradation of the material. Dry the interior with a hair dryer on a low setting to partially inflate the sleeping mat, then deflate and repeat a few times.
For long-term storage, follow instructions for your sleeping mat; some need to be inflated (e.g. Therm-a-Rest©), while others can be left deflated (e.g. NeoAir©). In general, self-inflating mats should be stored semi-inflated for good air circulation, whereas air mats should be stored loosely and not folded along the same crease lines each time. Choose a cool, dry place that doesn’t have extremely hot temperatures.