People living, working and socialising in Bristol are being asked to wear masks and meet outdoors to prevent the spread of Covid-19.
In a joint statement, local leaders and health bosses have issued a plea for people to "take action" to protect vulnerable people and prepare for a "challenging winter".
The statement says: "We know that everyone has had to make a sacrifice. Now we are seeing lives and livelihoods are being disrupted once again - the virus is thriving as people gather indoors and the cold weather sets in."
It comes after an estimated 40,000 people in the South West were wrongly told they had tested negative for Covid-19 due to a lab error.
Covid rates in the South West have since hit a new record, with Bath and North East Somerset seeing some of the highest rates in the country.
Case rates in Bristol have also risen and now local leaders have said they "expect" and "strongly recommend" that people adopt "precautionary measures".
This includes isolating when unwell, getting a PCR test if you experience coronavirus symptoms and taking regular lateral flow tests.
People are once again being asked to wear a face covering in crowded areas like supermarkets and in shops, on public transport and indoor settings.
"Meet outdoors where you are able, or if you’re meeting indoors, make sure to open a window or door to let in blasts of fresh air – this is particularly important when you’re meeting or socialising with people or family members who may be more vulnerable to severe illness," the statement continued.
People are also being asked to attend flu jab and Covid booster appointments without delay.
Leaders say the city is in a better position than it was this time last year due to the success of the vaccine rollout - but warn of a difficult winter ahead.
The statement says: "Bristol must prepare for what is likely to be a very challenging winter – for us as individuals and families, but also for our NHS and social care colleagues, our schools, universities and colleges and our local business."
It adds frontline NHS staff are under "considerable pressure" and asked for people to be patient with healthcare staff.
"They are doing their best in tough circumstances," it said.