Dr John-Paul Loughrey, vice-president of the Royal College of Emergency Medicine (RCEM) Scotland, conceded the medical body was “deeply concerned” about this winter.
The college has estimated one in 72 patients waiting between eight to 12 hours in an emergency department can die.
It comes as the latest A&E figures showed 3,048 patients had waited more than eight hours and 1,276 more than 12 hours in the week to December 4.
The warning was issued as it was revealed Scotland’s cancer treatment waiting times had fallen to their worst performance on record in a situation labelled a “full-blown disaster” by opposition political parties.
Dr Loughrey said patients were continued to face “exceptionally dangerous long waits”.
"We estimate that one in 72 patients waiting between eight to 12 hours in an emergency department can die as a result of these waiting times,” he said.
“But these are data. The reality is emergency departments are overcrowded and in extremis. Patients with an array of different needs and care are packed in, facing high-risk and uncomfortable waits on trolleys in corridors.
"There is a lack of privacy, a lack of dignity, staff are stretched thinly, meaning patients find it difficult to get the things they need – be it food or water or bathroom facilities, while they wait hours for a bed. Meanwhile, ambulances queue outside our emergency departments with more patients waiting to simply get in.”
Dr Loughrey has called for an extra 1,000 acute beds to be opened and the social care workforced to be strengthened to ensure the timely discharge of patients and tackle the “root of the crisis”.
But Health secretary Humza Yousaf pointed out there had been a slight improvement in the latest A&E figures despite increased attendances.
A& waiting times reported yesterday had improved from a record low, but less than two-thirds of patients are being seen within the target time. New figures showed 63.4 per cent of people who attended A&E in the week to December 4 were seen and subsequently admitted or discharged within four hours.
Mr Yousaf said: “Pandemic backlogs, Brexit-driven staff shortages and inflation costs have all contributed to make this the most challenging winter the NHS has ever faced.
"In addition, the level of delayed discharge is driving up A&E waits, which is why we are working with Health Boards to ensure people leave hospital without delay, freeing up vital beds for those who need them most. We will continue to see fluctuations in figures over winter, despite this, I am clear that A&E performance is not where it needs to be.
Public Health Scotland data separately showed just 74.7 per cent of cancer patients started treatment within the official 62-day standard across July and September.
It is a record low compared to the 79.3 per cent in the previous quarter and 83.7 per cent at the end of December 2019.
No health boards met the standard of 95 per cent in this quarter – and nationally it has not been achieved since the end of 2012.However, 4,161 eligible patients were referred for the 62-day standard, which is an increase of 2.2 per cent from the previous quarter and an increase of 11.8 per cent from the quarter ending December 2019.
The 62-day standard is based on the time from urgent suspicions of cancer referral to first cancer treatment.Statistics also showed performance against another target – the 31-day standard from decision to treat to first cancer treatment – fell just short, with 94.3 per cent of patients seen compared to 95.5 per cent in the previous quarter and 96.5 per cent in the final quarter of 2019. The target was missed by NHS Grampian, Greater Glasgow and Clyde, Highland, Lanarkshire and Lothian.
Janice Preston, head of strategic partnerships for MacMillan Cancer Support in Scotland, said: “Cancer waiting times have been getting worse for years, and today’s figures show the worrying trend continues right across the country, even before the added pressure of winter is factored in.”
It is understood health boards are reporting workforce issues as one of the main reasons why the targets were missed.Ms Preston continued: “We know there’s not a simple fix, but the simple fact is that people with cancer in Scotland need and deserve a system that can treat them faster. “Despite today’s statistics, we want to make sure everyone hears a very clear message – please, if you have worrying or unexplained symptoms, get them checked out by your GP practice.”
Scottish Labour health spokeswoman Jackie Baillie said: “This is a full-blown disaster and there’s no doubt it will cost lives. NHS staff are exhausted and demoralised, and cancer patients are being left to deteriorate.
“The SNP have ignored warning after warning about the ticking time bomb of cancer cases they let pile up during the pandemic, and now we are seeing the consequences. We need urgent action if we are going to stand a chance of undoing the damage done by this dangerous negligence.”
Scottish Tory health spokesman Dr Sandesh Gulhane expressed his shock at the figures, saying: “These figures are truly terrifying. It is disgraceful that over a quarter of cancer patients are not starting treatment within two months.
“That will have a potentially devastating impact on their chances of survival. All of this is happening on Humza Yousaf’s watch, with cancer waiting times worsening every quarter since he became health secretary.”
Mr Yousaf said the Covid-19 pandemic had placed significant strain on the NHS, including cancer services. He said: “Despite those pressures, more patients were treated on both 62-day and 31-day cancer pathways this quarter compared to the previous quarter, the same time last year (Q3 2021) and the last full quarter pre-pandemic (Q4 2019).“The median wait for treatment on the 31-day pathway remains at four days, with over nine out of ten people being treated within the 31-day target.
“We’re investing £40 million over five years to support cancer services and improve waiting times, with a focus on urology, colorectal and breast with £10m released to boards targeted at these most challenged pathways.
“We are committed to finding cancer as early as possible which is why we are expanding Rapid Cancer Diagnostic Services across Scotland and yesterday published Scotland’s first optimal cancer diagnostic pathway for lung cancer, alongside £3m investment.”