People in all of England and the majority of Scotland needs to now stay in the home except for a small number of permitted reasons, due to new lockdowns get started in both nations.
Schools experience closed to most pupils in England, Scotland and Wales, while Northern Ireland could have an "extended amount of remote learning".
England's rules are expected to last until mid-February, even while Scotland's will end up being reviewed towards the end of January.
PM Boris Johnson warned the approaching weeks will be the "hardest yet".
It employs the UK reported an archive 58,784 cases about Monday, in addition to a even more 407 deaths within 28 days of a great test.
Announcing England's lockdown, Mr Johnson said hospitals were under "more pressure coming from Covid than anytime as the start of pandemic".
He ordered persons to stay indoors apart from for limited exceptions - such as for example essential medical needs, meals shopping, exercise and job that cannot be done in the home - and said schools and schools should immediately move to remote teaching in most of students.
And he said all good care residence residents and their carers, everyone aged 70 and over, all frontline health and social care employees, and the clinically extremely vulnerable might come to be offered one dose of a vaccine by mid-February.
As the rules become law in the first hours of Wednesday, people should follow them nowadays, the PM added.
Earlier on Monday, Initially Minister Nicola Sturgeon issued a good stay-at-home order for Scotland, beginning at nighttime and lasting before end of January.
Scotland's lockdown, which is for the mainland and Skye, may also see colleges closed to pupils, locations of worship closed and group exercise banned.
"It really is no exaggeration to say that I am more concerned about the situation we face now than I have been anytime since March last year," Ms Sturgeon said.
Wales, which has experienced a national lockdown since 20 December, said universities and schools would shut until 18 January for some pupils.
Meanwhile, Northern Ireland, which entered a good six-week lockdown in Boxing Day, ideas to place its stay-at-home communication into law, and can have an "extended period of remote control learning", the Stormont Executive said.
And in England, examinations will again deal with disruption. The prime minister said they would not happen as regular in the summer, while a government supply told BBC Media that A-Amounts and GCSEs will become cancelled.
Under England's new methods, support and childcare bubbles will continue, and people can meet one individual from another home for outdoor exercise.
Communal worship and lifestyle events just like funerals and weddings may continue, subject to limits on attendance.
Mr Johnson said even though a new, more infectious variant of the virus is spreading across the UK, vaccinating the most notable four priority groups by mid-February could allow constraints to be eased.
He added those people who are clinically extremely vulnerable will come to be contacted by letter and should now shield once again.