Over the years we have tightened our monitoring of temps in the BB to include requirements from various regulators. For example, we store room temp tissue for OR and have been recording temps from a thermometer there, but just recently we added an alarm to the side of the cupboard where it is stored.
In general, we check all alarms and temps for the various refrigerators, platelet rotators, freezers, etc. and record them once a day, documenting that the charts match the readings match the thermometers. All of our freezers and refrigerators are also monitored automatically by a computer system in engineering as a back-up. Also, everything is checked quarterly against calibrated thermometers.
Scott