Temperature Monitoring Equipment

Every storage unit must have a temperature monitoring device (TMD).

CDC requires a specific type of TMD called a "digital data logger" (DDL) for accurate temperature monitoring: 

  • Ultra-cold freezer: Use a DDL with a probe designed specifically to measure ultra-cold temperatures. 
  • Refrigerator: Use a DDL with a detachable probe that best reflects vaccine temperatures (e.g., probe buffered with glycol, glass beads, sand, or Teflon®).

For the thermal shipping container, use the Controlant TMD included in the container.  

data logger

CDC Vaccine Storage and Handling Toolkit, COVID-19 Addendum 



Page last reviewed: March 7, 2022