Which feature of a vaccine storage thermometer is essential for safety monitoring?

• A. It records humidity levels automatically
• B. It triggers an alarm when out of range
• C. It only displays the temperature at the end of the day
• D. It is optional and rarely used

Answer: (B)

The essential feature is the alarm that triggers when the temperature goes outside the safe range. Vaccine storage requires maintaining a strict temperature window (typically 2°C to 8°C). If the fridge temperature drifts, a timely alarm alerts staff to take immediate action—adjust the temperature, relocate the vaccines, or log and manage the excursion—so doses aren’t compromised. This rapid notification is far more protective than simply displaying the temperature at the end of the day, which could miss problems that occurred hours earlier. Humidity readings aren’t the primary safety concern for vaccine potency, and treating the alarm as optional contradicts the need for continuous, proactive monitoring.