Green’s Dictionary of Slang

(Aus.) to dress warmly.

1986		C. Bowles G’DAY 58: It's freezing, so they get rugged up and hit the road.
1993		M.B. ‘Chopper’ Read How to Shoot Friends 47: I am most concerned for her well-being, as she does not rug up warmly for the trip.
2004		T. Winton Turning (2005) 154: She rugged up in her mothbally coat.