legs with wheels. A carbonized cradle was found in the remains of Herculaneum left from the destruction of the city by the eruption of Mount Vesuvius in 79 CE. Use An infant bed is typically used after it is no longer safe to leave the baby in a bassinet. They have a lower center of gravity, more mass, a broader base of support and can hold a larger baby than a bassinet. Infant beds are more stable than bassinets and as such become desirable when a baby can roll, transferring inertia with their actions; a bassinet may tip, an infant bed won't without concerted effort. Around two or three years of age children are able to defeat their confinement and should be moved to a toddler bed to prevent an injurious fall while escaping their bed (falls account for 66% of emergency room admissions due to infant beds in the United States.). Placing a child into an infant bed can put strain on a caretaker's back as they typically have a mass between and at 36 months of age. To reduce the strain on those operating an infant bed, many infant beds feature: a mattress that can be in a raised position until the child is able to sit upright, and potentially lowered further when they are likely to begin standing (between 8 and 12 months). casters to make it easier to move the bed around. The American Academy of Pediatrics recommends that infants under 12 months share a room (but not a bed) with their parents, as this has shown to be protective against sudden infant death syndrome (SIDS). Other sleep environment factors include supine positioning (back sleeping), use of a firm sleep surface, breastfeeding, consideration of a pacifier (dummy), and avoidance of soft bedding, overheating, and exposure to tobacco smoke. Accessories Scientific research has shown that the mattress influences SIDS outcomes; a firm, clean and well-fitting mattress lowers SIDS risk. However, neither mattress materials nor using a second-hand mattress affect SIDS risk. It is common to place a waterproof membrane between the mattress and the bedding to prevent uncontained bed wetting from damaging the mattress. Bed sheets ought to fit the mattress tightly so that the child cannot become entangled and suffocate; a common safety recommendation is to short sheet the bed. Because of the pronounced risk of suffocation in very young children, and the danger of a