Join Date: Oct 2006
Location: London, UK
Programs: BA Gold, VS Silver, SQ Silver, IHG Plat Amb, Hilton Gold, Marriott Plat, Accor Silver, Radisson Prem
Posts: 16,872
4 hours is probably a recommended amount of time. If you don't want or can't arrive before then, you could try the Spa in the T5B lounge which is usually quieter.