Bord Gais will give €1m to those most struggling to pay bills during the big freeze.
The cash will be channelled through charities St Vincent de Paul and Alone.
David Bunworth, managing director of Bord Gais Energy, said the money would be aimed at the elderly and most vulnerable.
"We are conscious that the very cold weather has meant that customers need to use more gas to stay warm," he said.
"Although gas prices are down 25% since last year, we know that with the current economic and weather conditions some customers will still have difficulty meeting their gas bills."
Mr Bunworth urged customers, particularly the elderly, to ensure they keep warm during the prolonged cold spell.
Householders have also been promised reduced gas bills - but not until next month.
The Commission for Energy Regulation - which oversees Bord Gais and ESB prices - came under fire for not cutting prices ahead of the winter.
The regulator rubber-stamped an 8% drop in gas bills for homes and smaller businesses, to come into effect on February 1, when the worst of the current freezing conditions are expected to be over.
St Vincent de Paul, Fine Gael and Labour said the price reductions could have been better timed, long before winter.