The Cryo Data Logger PCE-LTD 100 can record temperatures ranging from -80 °C to +70 °C. The prefix "cryo" comes from Greek, where "kryos" means cold. Cryo data loggers are devices that can measure and record particularly low temperatures. With a measurement range starting at minus 80 °C, the Cryo Data Logger PCE-LTD 100 is suitable for temperature monitoring during the transport and storage of blood plasma, vaccines, and dry ice made from solid carbon dioxide. Especially during the transport of vaccines related to Covid-19, providing evidence of a consistently maintained cold chain from production to vaccination is crucial. Since some vaccines must be transported at very low temperatures, this also requires the use of specially designed measuring technology. Vaccines that need to be stored at -70 °C, for example, are partially transported in specialized containers with dry ice. Due to its robust and compact design and a special battery adapted to the conditions, the Cryo Data Logger can be easily used in various cooling containers and refrigeration devices. The high protection rating of IP 67 ensures that water and foreign objects cannot penetrate the Cryo Data Logger, allowing for thorough and hygienic cleaning. The special battery is suitable for low temperatures but has a significantly shorter runtime at extreme temperatures. At temperatures between -80 °C and -70 °C, the Cryo Data Logger can store measurement data at 15-minute intervals for up to 30 days with this battery. The highest accuracy of the Cryo Data Logger is ±0.5 °C in the temperature range of -30 °C to +70 °C. In the range of -80 °C to -31 °C, the accuracy is ±1 °C. The Cryo Data Logger has an internal memory for 17,280 measurement data points.