A mattress system comprising a mattress with two sets of interconnected chambers and a connector 126 which is joined to both of them wherein the connector is configurable between a first mode which defines airflow paths into each set of chambers with no airflow between the sets of chambers and a second mode in which the connector defines a path between the sets of chambers wherein the connector is arranged such that connection to an air pump automatically configures the connector to the first mode. An overpressure valve 166 may be provided which may be closed off in the first mode. Disconnection of the pump may move the connector to the second mode and biased stop valves 148 may be employed which are displaced upon connection of the air pump. The mattress may be designed to reduce pressure sores.
