Met Éireann has said it will be very cold in the coming days, with ice and low temperature warnings due to come into effect from Thursday.
The forecaster has warned of “hazardous conditions” with temperatures falling to as low as minus four degrees.
A yellow ice warning comes into effect in the early hours of Thursday morning and remains in place until midnight. A separate yellow low temperature and ice warning is in place from 10pm on Thursday until 10am on Friday.
Age Action has said it is concerned some older people may be reluctant to turn on their heating due to anxiety over bills, with gas prices having increased in recent months, aggravating broader cost-of-living pressures.
On Monday, Minister for Social Protection Heather Humphreys announced the largest ever expansion of the Fuel Allowance Scheme which she said was expected to see over 80,000 additional households qualify for a payment for the first time.
“The one thing I do not want to see is any old person afraid to turn on their heating,” Ms Humphreys said. “Our senior citizens have worked hard all their lives; they have put in their shift and I want to make sure they can live in comfort.”
Meanwhile, the AA has urged motorists to ensure vehicles are prepared for extreme weather.
There will be a cold start to Wednesday morning with frost, icy stretches and some fog in places. Many areas will have a dry day with spells of crisp winter sunshine.
However, there will be a few showers in northern and northwestern coastal counties, some of hail or sleet while highest temperatures will be between just two to six degrees in light or moderate northerly breezes.
It will be mostly dry across Leinster and Munster overnight, but scattered showers will affect Connacht and Ulster, some turning wintry, especially over high ground.
Met Éireann said there will be “an icy start” on Thursday with patches of freezing fog in places. A band of wintry showers over Ulster will track southwards over the country. Some accumulations of snow are possible, especially in Midland counties and over high ground leading to hazardous travel conditions.
Sunny spells and scattered wintry showers will follow with highest temperatures between zero and three degrees in light north or variable winds.
A severe frost will set in quickly after dark and it will turn icy in places. There will be some wintry showers in Atlantic coastal counties of Connacht and Ulster and also for a time in parts of east Leinster.