A senior doctor has warned that "massive" numbers of coronavirus patients are filling Welsh hospitals and his colleagues are being "stretched to the limit".
It comes after a Welsh health board issued an urgent appeal for help to care for coronavirus patients in their critical care departments.
A further 70 coronavirus deaths and 4,142 new cases were reported by Public Health Wales on Monday.
Those figures cover a 48 hour period - 9am 24 December to 9am 26 December - instead of the usual 24 hour period.
It brings the total number of coronavirus related deaths in Wales to 3,368.
Dr Andrew Lansdown, a consultant endocrinologist at the University Hospital of Wales in Cardiff, said the new variant of the virus is contributing to increased demand on services.
Speaking on BBC Radio Five Live Breakfast, he said: "It's starting to sound a bit like a cliche but it really is true that these are unprecedented times, we really have felt stretched to the limit.
"In the past week or two things have become relentless, we're under extreme pressure and the numbers of patients coming through now with coronavirus are massive."
On Sunday, Cardiff and Vale University Health Board put out an appeal on social media calling for "assistance from medical students or other staff groups who have previously supported with proning patients", the process where people are turned onto their front to help with breathing.Dr Lansdown said: "My ward has recently turned into a coronavirus ward to make way for these patients and on the weekend [we had] to tweet for extra help because of the impact of that.
"It's not just the new variant, which seems to be spreading faster, you've also got the usual winter pressures at the hospital as well as staff themselves who are ill, self-isolating."
The plea for help came as figures for hospitals across Wales showed that intensive care wards are at breaking point.
Dr Lansdown also said that staff were exhausted by a pandemic which has now lasted nearly a year."During the first wave there was a large resource of energy in staff," he added."Also, a lot of regular procedures were cancelled whereas now in the second wave it's quite different.
"We can see a lot of staff fatigue, at all levels, plus staff are trying to balance the regular outpatient work and the regular work that we're doing, so we're really seeing that pressure during the second wave."