There is described a mattress system (20) comprising a mattress, an airflow driving device (14) and a heat adjustment unit (28). The mattress has a mattress cover (24) enclosing an internal mattress (10) such that a mattress air chamber is formed between the internal mattress and the mattress cover. The airflow driving device is in fluid communication with the mattress air chamber via an air chamber inlet and an air chamber outlet. The airflow driving device is operable to drive an airflow through the mattress air chamber from the air chamber inlet to the air chamber outlet. The heat adjustment unit is for heating or cooling the airflow so as to control a temperature of the airflow within the mattress air chamber. There is also described a mattress. In addition, there is described an apparatus for providing a temperature-controlled airflow through a mattress air chamber connected to the apparatus.