Critical temperature bottle thermometers are filled with a biosafe, glycol/water solution or with beads, pellets, or sand. They are built with an analog thermometer in the bottle with part of it coming out of the top for easy reading. They are placed into an environment that needs to be monitored, and the temperature reading mimics the temperature of the critical samples. These bottles are shatter-resistant and not impacted by power outages, the opening and closing of doors, or other sudden changes. These thermometers are intended more for verification than for logging, and are commonly used to measure temperatures in blood banks, pharmacies, hospitals, and laboratories. Select thermometers are NIST-certified.