Overnight temperatures could fall to minus 6°C in parts of the UK during the season’s first cold snap, as yellow cold-health alerts take effect in the North West and West Midlands.

The UK Health Security Agency’s alerts cover the two English regions from 9am on Thursday until noon on Saturday. No other regions of England are currently under a cold-health alert, although the colder weather is expected more widely as air moves south from the north.

The agency warned that cold weather can increase demand for healthcare services and pose a greater risk to life for vulnerable people, particularly those aged 65 and over and those with pre-existing health conditions.

Dr Anya Gopfert, a consultant in public health at the agency, said: “This is the first cold-health alert of the winter, but we can expect more as we move further into the season.” She urged people to check on vulnerable friends, relatives and neighbours, and advised heating homes and dressing warmly.

The forecast is not exceptional for the time of year, but that does not remove its health implications. Met Office spokesman Stephen Dixon described the approaching weather as the first cold spell of late autumn, with a fairly harsh frost likely in some places and drivers facing the prospect of scraping their cars in the morning.

Snow is possible over higher ground in northern Scotland, where a couple of centimetres could accumulate on the highest ground. Dixon said such conditions were not particularly unusual for the season.

The outlook then becomes wetter. Rain is expected across western Scotland on Saturday before spreading across much of the country on Sunday, accompanied by potentially heavy showers. Around 30mm could fall fairly widely that day, particularly in the west.

There is also a chance of snow in the far north of Scotland on Monday morning. For those most vulnerable to the cold, the immediate advice is to keep warm and ensure someone checks in.