Gas turbine engine and intake for a gas turbine engine with a device to prevent ice forming

A gas turbine engine (10) comprising a nacelle (21) having an intake (12), the intake (12) defining a generally annular chamber (35), an engine accessory (33, 34) and a heat exchanger (36) for cooling a fluid of the accessory (33, 34) characterised in that the chamber (35) is closed and the heat exchanger (36) is disposed within the chamber (35) operable to provide heat to prevent ice forming on the intake (12) during engine (10) operation.