The Irish Blood Transfusion Service is looking for donors to help replenish its supplies, after a recent drop in donations.
The service has four-to-five days worth of blood in its blood bank, in most blood groups, due to a drop in donations in recent weeks.
"That's not a crisis, but we prefer for comfort to have between five and six days' worth of blood," said director of operations with the Irish Blood Transfusion Service Paddy Bowler.
Mr Bowler told Highland Radio that, while it was not unusual for people to stop giving blood at this time of year, it was still a concern.
"This often happens us at this time of year, as the evenings lengthen and people get engaged in other activities," he said. "It's a little uncomfortable. We're under a little pressure at the moment."
Donors can give blood at a series of clinics around the country.