With one in three people carrying COVID-19 without showing any symptoms, and a new, more infectious strain of the virus in circulation, the need to observe the government guidance has never been greater.
There are already hundreds of COVID-19 patients in Hertfordshire hospitals, and taking care of increased numbers of highly infectious patients - along with everyone else who needs medical care - is at risk of putting services under further pressure.
The impact of 'long Covid' also puts a strain on families who can find it challenging providing ongoing care to sufferers. Around 10% of mild coronavirus cases who were not admitted to hospital have reported symptoms lasting more than four weeks, and some hospitalised cases reported continuing symptoms for eight weeks or more following discharge.
Tracey Carter is the chief nurse at West Herts Hospitals NHS Trust, which manages Watford General, St Albans City and Hemel Hempstead hospitals. She said: "Sadly we are seeing too many people coming into hospital with COVID-19, more now than in the Spring. Please don't let you or your friends and family be one of them.
"Staff are already working flat out to look after patients and keep services running - but we can't do this by ourselves. We need everyone in Hertfordshire to do their bit and do the right thing by staying at home wherever possible. If you do go out, wash your hands, keep your distance, cover your face, and spend as little time as possible out of your home."
Dr Michael Chilvers is the medical director at East and North Hertfordshire NHS Trust which manages the Lister, Hertford County and New QEII hospitals. He said: "Now is the time to stop and think about the consequences for yourself, your family and others of whatever choices you make or whatever you do. The rules are in place for a reason and so we are asking local people to follow them. Staying in could save your life or the life of a loved one."
Darryl Keen, Hertfordshire's chief fire officer and strategic lead of the countywide response to COVID-19, said: "If your plans for New Year's Eve involve anything other than staying in, you need to put them on hold. Right now, the only way of protecting yourself and your family is to minimise the amount of time you spend outside your home. We should be under no illusions - the situation we are in right now is extremely serious. I urge you to think of others, including those working hard to treat people in our hospitals, and play your part."