6.2.2 Cold boxes and vaccine carriers
A cold box is an insulated container that can be lined with ‘conditioned’ ice-packs to keep vaccines and diluents cold — but not frozen — during transportation of vaccine supplies from the health centre, or to outreach sites. (We will explain what ‘conditioning’ ice-packs means in the next section.) Cold boxes can also be used for short periods of vaccine storage (from two to seven days, depending on the manufacturer) when the refrigerator is out of order or being defrosted, or if vaccines are being transported in a vehicle for a few days by mobile immunization teams.
Cold boxes are quite large. At Health Post level you may instead use a smaller insulated container called a vaccine carrier (Figure 6.4). Vaccine carriers are also lined with conditioned ice-packs to keep vaccines and diluents cold during transportation from the collection store at the health centre, or on journeys to outreach sites, and for temporary storage during Health Post immunization sessions. They are smaller than cold boxes and are easier to carry if walking, but they do not stay cold for as long — at most 36–48 hours with the lid closed (depending on the type).