The cold snap is likely to put a further strain on accident and emergency services already dealing with raised levels of flu and norovirus, as the number of flu-related deaths so far this winter rose to 120.
The latest figures from Public Health England (PHE) show there were 17 flu-related deaths during the second week of the year.
Separate statistics released on Thursday by NHS England show there were 12,600 ambulance delays of more than 30 minutes this week, down from 16,700 last week. Of these, 2,600 were delays of more than 60 minutes, down from 5,100.
But NHS England added that there has been a “marked increase” of reports of norovirus and they are now above the five-year average for this week.
An NHS England spokesman said: “Raised levels of flu and norovirus continue to put pressure on busy A&Es and other frontline services but today’s figures show pressures abating somewhat compared to the prior week, and with hospitals generally continuing to cope.”
“With a 90% probability of severe cold weather, icy conditions and heavy snow predicted up to Sunday January 21 in these parts of the country, the weather could increase the health risks in vulnerable patients,” NHS England added.
Janet Davies, chief executive of the Royal College of Nursing, said: “England’s accident and emergency departments took a step back from the precipice last week as fewer patients came by ambulance and fewer departments diverted patients elsewhere.
“However, the squeeze on beds is showing no sign of abating. Hospitals are full to bursting and patients are waiting in chairs, corridors and even on the floor for space on a ward – this is despite putting up almost twice as many makeshift beds as before Christmas.”
Dr Nick Scriven, president of the Society for Acute Medicine, warned the strain on already-stretched services could last for many more weeks, putting NHS staff at risk of getting ill themselves.
“We are seeing a sustained period of exceptionally high demand on a service that is only being kept safe by dedicated staff going beyond all normal limits,” he said.
“This is sustainable only for a week or two and we are now entering the third week of this crisis which will not relent for weeks yet even if admission rates reduce such is the crowding in our hospitals.
“The NHS and individual trusts must now give thoughts on how they can help their staff cope and not succumb themselves to illness brought on by exhaustion, which is now a real danger.”