Fire crews were called to a flat in Hassocks this morning following a report that a person had collapsed.
They were called just after 7am to help gain entry to the property in Keymer Road.
One fire engine was sent to the scene and after gaining entry a person was found conscious, a spokesman for the fire service said.
They added: “An emergency smoke alarm was fitted and we left at 7.56am. An ambulance was also in attendance.”