During the current heat wave, there have been fewer blood donors. We currently need blood from all blood groups.
The heat wave that has been going on for two weeks has reduced the number of donors. Normally some 800 people donate blood per day, but over the past few weeks, the number has done down to about 660. At the same time, the use of red blood cells in hospitals has been higher than predicted.
Due to the shortfall, the Blood Service has contacted donors by telephone and text message. Advertisements and social media have also been used.
The droplet barometer shows when help is needed
The droplet barometer on the Blood Service web site shows whether there is a need for blood of a particular blood group on any given day. The droplet barometer does not measure the real-time sufficiency of blood reserves at hospitals or the Blood Service; instead, its serves to instruct donors. The need for blood is affected by, for example, the number of blood donors in recent days, the use rate of blood at hospitals, and the estimated need for blood in the near future.
Sometimes a blood donor may receive an invitation to donate blood, even though the droplet of his or her blood group is full. This is because particularly platelets, which are only good for five days, are needed for patients. Donors who have not been personally requested to give blood should act as indicated by the droplets. Donors are always needed when a blood group's droplet is halfway down or lower – and latest when an invitation is sent.