An air mattress is an inflatable mattress/sleeping pad. Due to its buoyancy, it is also often used as a water toy/flotation device, and in some countries, including the UK, is called a lilo ("Li-lo" being a specific trademark).
For sleeping 
An air mattress, also known as an airbed is an inflatable mattress, the wide majority of which are usually made of PVC vinyl plastic although recently developed textile-reinforced urethane plastic or rubber versions exist. The deflated mattress can be rolled up or folded and carried or stored relatively easily, making them a popular choice for camping trips and for temporary bedding at home for guests. They are inflated either orally by blowing into a valve, or with a manual foot-powered or more commonly inflated via an electric pump. Some are even automatically inflating (up to a certain pressure - some additional inflation is also needed) just by opening the valve.
The three main categories for use of air mattresses are camping, temporary home use (guests) and full-time permanent use (in the bedroom). Some air mattresses are specifically designed to perform both functions (camping and guest use) while others are specifically designed for one purpose alone (permanent use in the home or RV). Other air mattresses are designed in shapes with wheel well cut outs specifically intended for use in vehicles such as pickup trucks or SUV's.
Lightweight, reduced-size and reduced-thickness air mattresses specifically intended for camping and backpacking are sometimes called sleeping pads, especially when a layer of foam insulation is added under the air chambers. Better quality air chambers, that are designed for permanent use in the home, are constructed of vulcanized rubber, covered in canvas or of polyurethane. These chamber(s) are then installed into a cloth shell or tic. Permanent air beds will look almost like conventional beds with the exception of having a hose (one air chamber) or hoses (two air chambers) coming out of the head of the bed. These hoses will be connected to an Air Inflator, with two outlet valves, that will have a remote control(s) so that each person can adjust the firmness of their side to ones own exact needs. The firmness can be adjusted up or down, with the simple push of a button, on the remote(s).
Some government safety agencies have warned against letting infants sleep on air mattresses, because they can be too soft and suffocate smaller children (especially those below the age of 8 months) within folds or while entrapped between the mattress and the bed case. Additionally there have been several recent governmental studies and regulations enacted due to the poisonous nature of the phthalates and dioxins contained within all PVC vinyl air beds and other soft vinyl products. The European Union has made similar efforts to prevent the use of vinyl materials in toys and bedding.
Air beds 
Larger, more elaborate air mattresses ("air beds") have come on the market in recent years that are intended for guest use, or as permanent beds in the bedroom. Sizes range for temporary air beds range from twin to king, however few guest bed manufacturers offer king, as the majority of guest air beds are sold outside of the United States, where king size mattresses are not standard. Most permanent air beds can use conventional (standard) sheets and bedding, which are very easy to find, for purchase. California King or Western King sheets and bedding may be more difficult to find as this size was originally conceived for the waterbed industry.
Raised guest or temporary beds are typically raised off the ground to keep users away from the floor and offer a more traditional mattress experience. Though 'raised' air beds are off the ground they are not designed for full-time use, as the base of the bed is an air chamber and not a solid foundation.
Health benefits 
Air mattresses can also improve the quality of life (and potentially provide some measure of relief) for people who suffer with back pain. Having the ability to adjust the firmness of a mattress to accommodate different body shapes, sizes, and weights, can be a factor in the healing process. Additionally, air mattresses manufactured without the use of materials that may release VOCs or other toxic compounds from the manufacturing process (which can exacerbate allergies in children or other sensitive individuals) are available.
For recreation 
As a water toy 
The term air mattress may also refer to a certain inflatable swimming pool or beach toy, which has an air-sac "pillow" and several (usually four or five) tubes running its length. Also called a "lilo" (UK), "pool air mat", "air mat", "pool lounge", or "float(ing) mat(tress)", it is used to recline on the water surface. Although it bears some resemblance to an air mattress, it is typically not built as strongly and may not reliably stay inflated all night long, making it impractical for use as a bed.
In Australia, many bushwalkers go "liloing" down canyons, creeks, and rivers. The attraction of liloing is that a lilo can easily be carried to the head of a river, and portages over otherwise impassable blockages are far easier with a lilo than with a canoe or a packraft. Liloing also allows canyoners who have abseiled through tight rock squeezes to enjoy long pools at the base of the canyon.
For longer trips, a backpack with waterproofed contents is wedged / tied to the 'neck' of the lilo (i.e. the junction between the body of the lilo and its pillow), and the liloer sits with the small of their back supported by the backpack so that only their seat and their upper hamstrings are submerged. In this position a small paddle assists manoeuvrability through rapids, but a more versatile approach is to use light hand-paddles. Note that if the liloer falls off in a rapid, they will instantly need to use their hands for survival (so as to avoid getting a foot trapped and having their face pushed underwater), so hand-paddles are best made of light plastic (e.g. cut from the sides of a sturdy plastic container) and loosely looped over the liloer's wrists. Many liloers wear helmets, as falling off and knocking oneself unconscious against a rock is a common danger. Fewer liloers wear buoyancy vests, as water in rapids is often too aerated to allow anything to float, and sometimes sinking to the bottom of a (hopefully snag-free) stopper is the only way of being flushed downstream. A wetsuit over the legs protects against abrasions, and can somewhat cushion bumps to shins, knees, and the coccyx. Wetsuit booties or elasticised ankle supports or lightweight basketball shoes that cover the ankle are particularly welcome over the ankles, which can otherwise become tender due to repeated bumps. (If wearing lace-up shoes that cover the ankles, lacing only the lower eyelets may assist escape from drowning if a foot becomes trapped in rocks.) Bulky boots or any loose clothing (such as untucked pants) that increase drag in the water can dangerously impede agility when attempting to wade through swiftly flowing water. New liloers should seek advice on what footwear grips best, as most running shoes give sub-optimal grip. In Australia, the cheap Dunlop Volley tennis shoe has remained essentially unaltered for many decades, and is regarded as essential by many river hoppers, roofers, and bushwalkers.
Many liloers consider that lilos need to be of sturdy rubberised cotton to withstand abrasion and snagging against sand, rocks, and partially submerged fallen timber. However, some liloers have discovered that very finely woven synthetic plasticised fabrics and even vinyl fabrics tend to slide over snags instead of catching on snags. Liloers have done week-long trips over grade-3 rapids with lilos weighing 1.2 kg or less; such lilos dry much faster and are much lighter to carry than rubberised cotton lilos weighing 3 kg. Some liloers smear glue over parts of the lilo that experience a lot of abrasion, such as the base of the corners at the foot of the lilo.
Most rips or punctures to a lilo can be easily repaired using contact glue and spare fabric. Some liloers use a portable stove to speed up drying the lilo for initial application of glue; heat also assists drying the applied contact adhesive ready for joining. If a lilo is left unwetted in the sun, the expanding heated air in the lilo may pop a seam. Seam pops require 2-stage surgery to repair: the repairer must slit open the fabric adjacent to the popped seam, re-glue the seam (and the internal tape that stops it from peeling apart) from the inside, and then repair the slit that was made for the surgery.
Lilos allow considerable versatility for people travelling by water in wilderness areas. Older-style inflatable rafts that do not have a built-in inflated-floor allow the rafter to wedge in a suitably sized lilo at the bottom that provides comfortable and versatile buoyant flooring. Lilos made of synthetic material dry quickly, and lilos are the most comfortable way of sleeping on a bank of large rounded rocks. (In colder weather the sleeper will need insulation between the sleeper and the lilo, as traditional lilos provide negligible insulation.) Lilos can be used in combination with rafts, with half the party paddling supplies in a raft, with the other half of the party paddling alongside on their lilos - rafts are a faster and more comfortable mode of transport, but are far heavier to carry in to a distant river head. Backpacks can float through the water with surprisingly little drag, and can be easily towed (with a 3 metre cord, in still water) by a liloer who has not lost their paddles. A short tape attached to a backpack makes it easier to tug along the backpack when walking in shallow water.
In Australia it is now difficult to find air mattresses suitable for liloing, because improvements in mattress technology have supplanted the lilo. Light-weight campers are likely to favour a self-inflating sleeping pad, while campers who do not care about weight are likely to favour a large thick flocked air mattress with no built-in pillow. (Lilos suitable for liloing have a substantially sized pillow to provide extra support for the upper body / back pack.) Whereas previously various models of suitable lilos were cheaply and widely available, the once-common recreation of liloing is now impeded by a poor supply of suitable lilos.
See also 
- Air mattress (definition on Princeton WordNet. Accessed 2008-08-10).
- "lilo". Compact Oxford English Dictionary. Oxford University Press. 2009. Retrieved 2009-05-10.
- Deadly Danger: CPSC Urges Parents To Not Place Infants on Air Mattresses (from the Consumer Product Safety Commission government website, United States. Accessed 2008-08-11).
- "A new mattress can relieve low back pain and improve sleep quality".
- "4 PVC-Free Inflatable Mattress and Guest Bed Options".
- "Indoor Chemicals Linked to Respiratory and Allergic Effects in Children", California EPA, 2008.
- "Indoor Residential Chemical Emissions as Risk Factors for Respiratory and Allergic Effects in Children: a Review", Indoor Air Journal, vol. 17, pp. 259–277, 2007.
- Media related to Air mattresses at Wikimedia Commons
- The dictionary definition of lilo at Wiktionary