beds are used for children and teens in summer camps. Some inexpensive hostels provide bunk beds for guests. Bunk beds are used for children in private homes. A loft bed is similar to a bunk bed, except there is no lower bunk. This leaves space underneath for storage, other furniture, a desk etc. A captain's bed (also known as a "captain bed", "chest bed", or "cabin bed") is a platform bed with drawers and storage compartments built in underneath. A camp bed (also "cot") is a simple, temporary, portable bed used by armies and by campers. Cots are also used to provide a sleeping surface for refugees and other homeless people during disasters, floods, or other crises. A canopy bed is similar to a four poster bed, but the posts usually extend higher and are adorned or draped with cloth, sometimes completely enclosing the bed. Examples include the lit à la polonaise and the lit a la turque. A curtained bed is a luxury bed with curtains. A daybed is a couch that is used as a seat by day and as a bed by night. Usually it has pop up trundle which is used as bed in the night. A futon is a traditional style of Japanese bed using a mattress on a wooden frame. Futons are also available in a larger Western style which can fold halfway for sitting. Futons were traditionally made with cotton, but in the 2000s, many futons include synthetic foam. A four poster bed is a bed with four posts, one in each corner, that support a tester. A hammock is a piece of suspended fabric or netting, used on ships and in some homes. A hideaway bed, invented by Sarah E. Goode in response to the needs of apartment-dwellers, folds up into another piece of furniture, such as a shelf or desk, when not in use. A hospital bed is specifically designed to facilitate convalescence, traditionally in a hospital or nursing facility, but increasingly in other settings, such as a private residence. Hospital beds are typically adjustable, so that the head or feet can be raised or lowered. Modern hospital beds commonly have wheels to assist in moderate relocation, but they are larger and generally more permanently placed than a trolley (US: gurney). The "hospital bed" is also a common unit of measurement for the capacity of any type of inpatient medical facility,