The Scottish government is to toughen its Christmas guidance, with people being urged to not stay overnight in another house unless it is unavoidable.
First Minister Nicola Sturgeon said the safest way to spend Christmas was “unequivocally” to stay within your own household and your own home.
And she said any interaction with other households should ideally be outdoors.
But those who feel it is essential to visit another household indoors should limit the time they spend together.
The new strengthened guidance will be published by the Scottish government later on Wednesday.
It comes as Prime Minister Boris Johnson announced that the four UK nations had “unanimously” agreed to keep relaxed Christmas Covid rules in place between 23 and 27 December.
But some advice will change in different parts of the UK, and sterner warnings will be issued to urge people to keep social contact low.
Wales has already said it will be advising that people from only two households, rather than three, should mix over the festive period.
Ms Sturgeon told her daily coronavirus briefing that the Scottish government would also be issuing strengthened guidance.
However, the current limit on no more than eight people from three households meeting indoors in Scotland will remain in place, with Ms Sturgeon saying it would not be fair or realistic at this stage to remove that flexibility.
She said rates of the virus were currently lower in Scotland than other parts of the UK, but warned against complacency.
The first minister said her government’s latest advice was to:
The first minister went on to say that the Scottish government recommends against travel from areas with a high prevalence of coronavirus to parts of the country with a lower prevalence.
She added: “If you haven’t made plans to form a bubble, please don’t.
“If you are still swithering, please decide against. And if you have made plans but think they are not really essential, please think about postponing until later in the year.
“The reality is that this Christmas simply can’t be normal. But we have every reason to hope that next year’s will be much more normal.”
Prime Minister Boris Johnson told the House of Commons that people “should exercise extreme caution in the way we celebrate Christmas”, adding it was “absolutely vital” that people show “a high degree of personal responsibility”.
He urged people to be particularly careful when they come into contact with vulnerable people – and should avoid contact with elderly people “wherever possible”.
The four UK nations previously agreed a set of rules for the festive period, which has been set down in legislation and is not expected to change – even though the guidance has been updated.
Two leading health journals – the British Medical Journal and the Health Service Journal – warned earlier this week that two leading journals said the “rash” decision to ease restrictions across the UK would “cost many lives”.
And they warned that a new strain of coronavirus that has been detected in the UK, including some cases in Scotland, “has introduced further potential jeopardy”.
Global public health expert Dr Andrew Lee from Sheffield University said the Christmas period was a difficult balancing act for all politicians.
He told BBC Scotland: “They are all trying to avoid being The Grinch, but the numbers aren’t looking good.
“If we have super-spreading over Christmas, we will have a bumper number of infections come January.”