Watch Dr Toby Slade speak about pressures at the RCH
Hospital staff in Cornwall are "mentally and physically exhausted" as they continue to work under "extreme" pressure.
The Royal Cornwall Hospital declared a critical incident last week - and say pressure is continuing due to a "combination of factors".
These include an increase in Covid patients and issues with bed blocking.
The Treliske hospital says it is facing "unprecedented" challenges - while staff are "tired" and working in "exhausting" conditions to keep patients safe.
It has more than 40 patients with Covid-19, while another 70 patients are fit to be discharged but cannot be found beds in social care.
While the hospital is caring for more patients with coronavirus compared to last week, the total number of patients in hospital is down compared to the peak last year.
Royal Cornwall Hospital's medical director for urgent and emergency care Dr Toby Slade said: "The pressures have been extreme, both in Cornwall and across the south west and in fact, the wider UK.
"Some of the most significant pressures are due to the difficulty of us being able to discharge patients from the hospital. We currently have 70 patients in the hospital and a large number across the county in community hospitals, that are medically fit for discharge and are awaiting social care beds.
"That, combined with the pressures that we've had due to Covid and also, obviously, we've had half term week - high numbers of holidaymakers in the county - has given us unprecedented pressures, really."
Dr Slade said the stress on the hospital is a result of a "combination of multiple factors", including 42 patients with coronavirus - of which five are in intensive care.
"Those numbers are up five from last week and we know as we look into the winter, we're potentially going to see numbers possibly climbing again," he added.
This is causing a direct impact on patients, with waiting times increasing in the hospital due to a lack of available beds.
Dr Slade said: "From an emergency care point of view, the largest impact is the delays in being able to offload ambulances at the front door.
"In terms of care across the hospital, certainly elective procedures and surgical procedures... Certainly, we're having a huge amount of difficulty trying to provide elective cover but the team is doing everything they can to get those procedures done on patients as soon as possible."
This level of "unprecedented" demand on the hospital's services is causing hospital staff to feel exhausted, he said.
"I think the staff are doing an incredible job, both within the emergency department, across the wider hospital, the paramedics crews, the health and social care teams across Cornwall - really going above and beyond."
He added: "I think they are tired.
"It is mentally and physically exhausting and I am just very grateful for the amount of effort and hard work they are putting in to keep patients safe in Cornwall."
But Dr Slade also tried to reassure people there are fewer patients being admitted to the hospital with coronavirus than during the peak of the second wave last year.
"The total number of patients in the hospital are less than we had at Christmas... and at it's peak we had just over 100 patients in the hospital with Covid, to give you an idea of how that compares," he said.