Preventing vaccine freezing is one of the biggest barriers in vaccine management. Toward addressing this challenge, B.P. Koirala Institute of Health Sciences in Dharan, Nepal, in collaboration with PATH, conducted a field evaluation of freeze-preventive vaccine carriers (FPVCs) in 24 health facilities located across one hilly district and one plains district of eastern Nepal. The primary study objectives were to evaluate the performance, acceptability, and fit of the FPVCs within the existing immunization system.