Warning signs on plugs and circuit breakers. Thermometers in both refrigerator and freezer. Temperature of refrigerator and freezer must be checked each morning and recorded in a log sheet or calendar. Don't store food in refrigerator or freezer - they should be opened only for temperature checks and vaccines. Power is being interrupted.
Refrigerator is too cold.
Varicella is the most fragile of the vaccines. Don't let the refrigerator and freezer doors stand open. Check refrigerator and freezer doors each night. Keep liquid bulk in the refrigerator and freezer packs in the freezer - this maintains temperature when doors are opened and in case of power interruption. Check temperature and contact manufacturer if there is any question about the condition of the vaccine.