Watch ITV Cymru Wales' video report by Kelsey Redmore
Consultants working on the front line treating the sickest coronavirus patients have told ITV News they don't know how long staff can keep "going the extra mile", as cases continue to rise around Wales.
It comes as those hospitalised with Covid-19 have more than tripled within a month across the country.
The latest data from the Welsh Government shows those confirmed with the virus in hospital currently stands at 498 as of 16 September.
On 16 August, this number was just 133.
Dr Chris Gough an intensive care consultant at the University Hospital of Wales in Cardiff, said staff are "exhausted" due to having to treat more Covid patients, as well as non-Covid patients, with about 20% of ITU beds being taken up by people needing treatment for the virus.
"The staff are exhausted and really tired and have been working so hard, and it is busy. We're busy with Covid and we are busy with non-Covid, and the two things combined mean it's really busy and really pressured and pretty exhausting."
"We haven't just stopped having car crashes and people falling off ladders and doing all the other things that they do, and we're still having to care for those people as well. And so the two things combined, as well as a huge backlog of work that's built up over the last year or so, means that we're working busier than we've probably ever been before."
His comments come on the day the Welsh Government announced it will be introducing Covid passes for those wanting to attend large events and nightclubs in Wales - as part of a five-step plan to reduce the rising rates of transmission.
He said the majority of those most unwell are unvaccinated people.
"Certainly we are getting very few patients who are fully vaccinated, unless they have other medical conditions that mean that maybe the vaccine would be less effective for them, but predominantly we are seeing people who are unvaccinated.
"But, also that comes with a bit of a burden itself because we see people, very upset at their sickness, saying to us - "I wish I'd had my vaccine when I had the chance."
"And, you know, there's a lot of misinformation out there, but I think we all need to do what we can to try to increase the rates of vaccination because we will see the benefit."
Dr Gough also told ITV News he thinks it is going to get "worse before it gets better" as schools return as well as the winter period bringing extra pressures.
"I really worry for going into the winter and getting the usual flu pressures and winter pressures on the hospital what that's going to mean for us and I think my prediction is that things will get worse before they get better, but I think we've got really trying months ahead."
He called on the public to take steps to try and protect themselves.
"There's nothing revolutionary or new to be done it's doing the same things well. And we know that if you wear a face mask, keep your distance do good hand sanitization and get your vaccine that you are doing what you can to protect yourself those around you and the community."