People are being asked to donate blood, especially this week as supplies are low.
The bad weather has meant donations have dropped and the Irish Blood Transfusion Service need to get their supplies up.
Short supplies in some of the major blood groups means the IBTS will run extra services today in Dublin and Cork.
Spokesperson Paddy Bowler said they need people to donate especially in the build up to the holiday season.
"There will be an advertising campaign starting on Monday," Mr Bowler said.
"The purpose of that is to build stocks up in advance of the Christmas and New Year period because the demand for blood does not drop off that much during the period, while people's ability to donate does."