Emergency crews on alert for 'mad' Friday
Emergency crews across Wales are expecting one of the busiest nights of the year as revellers make the most of the final Friday before Christmas.
Known as "Mad" or "Black Friday", it marks the start of the festive season for many who are finishing work.
A woman has already been arrested by North Wales Police for being "drunk and urinating" in public at 16:00 GMT.
In Cardiff, there is a temporary triage unit in the city centre, while there is a help point in Swansea.
Swansea A&E unit bosses have appealed to party-goers to show restraint. They said alcohol-related issues at Halloween saw the hospital inundated with cases, which had a knock-on effect for four days.
The alcohol treatment centre (ATC) in Cardiff dealt with 32 people last Friday compared with 52 people in the week leading up to Christmas 2013.
It operates during busy periods to ease the pressure on emergency unit staff at the University Hospital of Wales.
"It's not a pretty job," said senior nurse Wayne Parsons, reflecting on the work at the ATC last Friday.
"We had to wash the walls down twice after patients vomited everywhere."
The help point in Swansea has been set up in The Strand between 22:00 and 04:00 GMT.
Bosses at Swansea's Morriston Hospital and the Princess of Wales Hospital, Bridgend, said they are already working flat-out and "worse-for-wear revellers" will only make matters worse.
Emergency consultant Andy MacNab said: "No-one wants to stop people having a good time at Christmas, but you really don't need to drink to excess to do so."
Health officials and the Red Cross will be running welfare centres in Wrexham and Rhyl.
Denbighshire council has worked with North Wales Police to provide taxi marshals in Rhyl over the festive period to try to ensure people's welfare.