A firefighter has been rushed to hospital after going into cardiac arrest whilst fighting a fire at Greta in the Hunter Valley.

Fire broke out late this afternoon during cathophopic conditions threating homes and lives at Greta near Cessnock in the Hunter Valley.

Fire crews have worked through the afternoon and night to bring this fire under control.

The fire is now downgraded to advice level for now as the southly change is set bring 90km winds this fire may break containment lines.