Residents of Lothian have been urged to “act now” to stop an “alarming” rise in coronavirus in the area.
The health board has issued a plea, asking people to follow guidance to stop the spread of the virus.
East Lothian will move to level three at 6pm on Friday, joining West Lothian in that particular tier of restrictions.
Latest figures show infections have risen across the Lothians in recent weeks, with the East of Scotland now considered a hotspot.
Calum Campbell, chief executive of NHS Lothian, said: “The rate of transmission is not only higher here now than it is in the west. It’s still climbing.
“So we need everyone to stop and think and do the right thing. It is the responsibility of each and every one of us to follow the rules so we can halt the spread of the virus and reverse this trend.
“If we can’t do that we may face more stringent restrictions. With Christmas round the corner that’s the last thing anyone wants.
“So, if you want to enjoy a safe, happy Christmas please take action now.
“Keep your distance from people who are not within your household, limit the number of people that you have interactions with and only shop for essential items.
“Wear face coverings, wash your hands. We all know what to do, so please, let’s pull together in one great big collective effort and do it.”
Katie Dee, interim director of public health at the board, added: “I know it’s difficult to not be able to do the normal Christmas and New Year festivities, but we all need to do our bit. If we don’t act now, the situation over the Christmas period could be bleak.
“The reality is, that unless we adhere to the rules more rigorously, we could soon be faced with tighter restrictions and even a further lockdown.”