THEWelsh Ambulance Service is urging the public to use its services wisely over the four-day Bank Holiday weekend.
The Trust is also reminding people to collect any medication they require and stock up on first aid supplies to treat minor injuries at home as it prepares for a busy weekend.
The NHS 111 Wales symptom checkers should be the first port of call for health advice, the service say.
Jubilee party-goers should also drink responsibly and treat emergency workers with respect.
Judith Bryce, Assistant Director of Operations (National Operations and Support), said: “We’re delighted to be celebrating Her Majesty the Queen’s Platinum Jubilee, and want people to have a safe and enjoyable celebration.
“We always see an uplift in demand as people take advantage of the long weekend, and this weekend is expected to be no different.
“More people are out and about socialising with family and friends, and this can lead to more people becoming ill or suffering injuries and requiring medical attention.
“While there are plans in place to deal with the increase in demand, we only have a limited number of crews and vehicles available which means that we need to prioritise those sickest patients first.
“It also means that people not facing a serious or life-threatening emergency could wait longer for a response or be asked to seek alternatives to an ambulance response.”
Hundreds of events are happening up and down the country to mark the Queen’s Platinum Jubilee, the 70th anniversary of the accession of Queen Elizabeth II in 1952.
The Trust is gearing up by putting extra resources in place on the road and in control rooms so that it can support as many patients as possible.
“We’re also working with partners on a number of multi-agency initiatives to mitigate demand, including alcohol treatment centres in Cardiff and Swansea to offset the number of people needing to attend the Emergency Department presenting with alcohol intoxication,” said Judith.
“Community First Responders will assist us not only by responding to calls in their local area, but by providing administrative support to colleagues in the Trust’s control rooms.
“We’re working hard behind the scenes to get us into the best place possible, but the public has a role to play too.
“Your GP surgery may be closed and your usual pharmacy may be closed or have altered opening hours, so check with them in plenty of time so you’re aware of any changes.
“Please also ensure you have all the medicines you need before the Bank Holiday, be it everyday medication like paracetamol or cough remedies, or getting your prescription filled.
“If you need advice about medication or prescriptions during any out-of-hours period, a pharmacist should be your first port of call.
“If your usual pharmacy is closed, search for an open pharmacy near you on the NHS 111 Wales website.
“The NHS 111 Wales website should also be the first place you visit for health advice and information if you’re ill or injured and unsure what to do.
“Help us protect our precious resources for those who need us most.”