Does the Holideck airport lounge at Heathrow allow for the taking of showers? Can one take a nap here? Looking at the website I am guessing that there are no shower facilities, but would like to confirm.

Am flying into Heathrow's Terminal 4 from JNB via BA arriving at 6:25 AM and departing at 3:00 PM for Paris. Bags will be in Paris. Suspect that son will be very tired and might not want to take a trip into London. Any suggestions?