Large areas of Wales have been warned to expect severe weather conditions during the weekend, with snow forecast and temperatures as low as -7C promised.
Temperatures are set to stay low throughout the weekend with a risk of icy roads and travel disruption.
A Met Office yellow warning for snow and ice is in place for much of Wales until 12pm on Sunday.
On Saturday, the Met Office extended ice warnings in Northern Ireland, Wales and south-western England to cover snow until 12pm on Sunday.
Rural and mountain roads including the Crimea Pass to Blaenau Ffestiniog in Snowdonia were impassable due to snow and ice.
North Wales Police are asking people to take "extra care" on roads at to leave more room between yourself and the car in front.
Traffic Wales are also warning of poor driving conditions across the country.
What to expect?
Probably some icy patches on some untreated roads, pavements and cycle paths
Some injuries from slips and falls on icy surfaces
In a few areas, difficult travel conditions may occur quite quickly due to heavy sleet, snow or hail showers making surfaces slippery or even snow-covered
Met Office chief meteorologist Steve Willington said: "It is staying cold with daytime temperatures remaining only a few degrees above freezing in many places over the coming days and overnight temperatures dropping to minus 10C or lower in isolated spots.
"Although below average, these temperatures are not that unusual for this time of year.
"There is still a risk we could see some freezing fog in places particularly southern England, especially for Sunday and Monday mornings.
"There is also a small risk of a band of sleet or snow moving into the far South East on Sunday. If this happens it could potentially bring some disruption, especially to rush hour on Monday. A warning has been issued."
The UKHSA is advising people to look out for friends and family who are vulnerable in the cold and to ensure they have access to warm food and drinks, adding that people should maintain indoor temperatures of at least 18C (64.4F).
Dr Agostinho Sousa, consultant in public health medicine at UKHSA, said: "Cold weather can have serious consequences for health and older people and those with heart or lung conditions can be particularly at risk.
"If you have a pre-existing medical condition, you should heat your home to a temperature that is comfortable for you.
"In rooms you mostly use such as the living room or bedroom, try to heat them to at least 18C if you can. Keep your bedroom windows closed at night. Wearing several layers of clothing will keep you warmer than one thicker layer."
It comes as people on the lowest incomes in dozens of affected postcode districts in Wales are set to receive a £25 cold weather payment.
The Government payments have been triggered for eligible households in areas where the average temperature has been recorded as, or is forecast to be, 0C or below over seven consecutive days.