Vaccine carrier, thermometer, and monitor cards, 1994.

DENMARK - JANUARY 02: These items are designed to maintain the cold-chain in vaccine delivery. The monitor cards (with instructions in English and French) change colour if exposed to temperatures above the safe limit over a period of time. All the items were approved by UNICEF and the World Health Organisation (WHO) for use in the Extended Programme on Immunisation (EPI), and were supplied by the UNICEF Supply Division, Copenhagen, Denmark. The vaccine carrier, model IVC-3-002 was manufactured in New Delhi, India, the thermometer, model 66/380/0, was made in England, and the cards were made in Switzerland. (Photo by SSPL/Getty Images)