Calls to Wales' ambulance service were so high at the weekend, it was forced to announce it could not keep up with demand.
The 999 and 111 service saw unprecedented volumes with icy conditions hampering paramedics' ability to respond to emergencies.
The NHS' 111 phone line, which is run by the Welsh Ambulance Services NHS Trust, saw 10,000 calls on Sunday - which was its busiest ever day on record - and an increase of 300%.
More than 2,000 emergency 999 calls were also made which were 17% higher than last week.
Delays at hospitals as well as icy weather conditions across West Wales, Heads of the Valleys, and the M4, did not "help our ability to respond", it said.
On Monday, it issued a statement saying the decision to declare a "business continuity incident" was not made "lightly".
“Although we have stood down the business continuity incident, demand on the service remains high which is intensified by the pressures across the system."
“Extreme weather, coupled with a high call volume focused on falls and breathing issues overnight, has limited our capacity to respond safely and timely", Executive Director of Operations Lee Brooks said.
It comes as ambulance workers are due to strike on 21 December in a dispute over pay and working conditions.
Paramedics, emergency care assistants, call handlers and other staff are set to walk out in Wales and at eight other trusts across the UK.
Rachel Harrison, GMB national secretary, said: “Ambulance workers – like other NHS workers – are on their knees.
“Demoralised and downtrodden, they’ve faced 12 years of Conservative cuts to the service and their pay packets, fought on the frontline of a global pandemic and now face the worst cost-of-living crisis in a generation.
“No one in the NHS takes strike action lightly – today shows just how desperate they are.
“This is as much about unsafe staffing levels and patient safety as it is about pay. A third of GMB ambulance workers think delays they’ve been involved with have led to the death of a patient.
“Something has to change or the service as we know it will collapse."