Temperature monitoring for medicine and vaccine refrigerators

Published on November 7, 2026 · 6 min read

The problem with the paper sheet

A paper log shows what someone saw at the moment they walked past the refrigerator. Between one entry and the next, the hospital does not know what happened. If the temperature left the range at night or over the weekend, the sheet only tells you when someone reads it, and the entry depends on a person remembering to make it.

Sense, the SigaME monitoring module, was designed for these points: pharmacies, laboratories, refrigerators, freezers, and areas for vaccines, samples and blood products, where a variation outside the range must be noticed right away.

How the measurement works

Sense measures temperature, humidity, pressure and door status. The fixed devices of the infrastructure measure the temperature and humidity of each location, and the hospital sees a map by floor. Among the SigaME devices, the eTag measures temperature, humidity and altitude, with an optional external probe, and locates by Wi-Fi.

1. The sensor measures. The reading reaches the platform continuously, without depending on a round.
2. The profile evaluates. The reading is compared with the range of the profile chosen for that point.
3. The alarm fires. If the condition is confirmed, the alarm is created and the alert is sent.
4. The team acts and records. The corrective action is saved with the alarm.

Profiles with hysteresis and delay

A refrigerator has small variations all day, and a door left open for a few moments raises the temperature. If every deviation raised an alarm, the team would learn to ignore them.

That is why Sense works with ready-made profiles, such as 2 to 8 °C, that use hysteresis and delay. The delay gives some time before the alarm fires, and the hysteresis keeps it from switching on and off near the limit. For a vaccine refrigerator, if the temperature leaves the range for the configured time, the alarm fires and the alert goes up by e-mail.

What generates an alarm

Besides temperature outside the range, the alarm handles these situations:

1. Out of range. The measurement goes past the profile limits for the configured time.
2. Sensor without communication. The point stops responding, and the hospital finds out before trusting an old reading.
3. Missing data. There is a gap with no measurements that should have arrived.
4. Low battery. The alert arrives before the sensor stops.

From excursion to corrective action

Each exit from the range becomes a handled alarm, with the corrective action recorded and escalation by e-mail. Points in alarm always stay at the top of the board, which also has a TV mode, so the team acts first where it matters.

When the hospital uses Flow, a Sense alarm can generate the corrective action task for the right team. That way, the alert does not depend on someone looking at a screen.

Calibration and reports

Sense keeps the certificate, the validity and the correction of each sensor and warns when calibration is about to expire. This applies to sensors for blood products and samples, for example.

The compliance reports are daily, monthly and by department, in PDF. They replace the manual paper log and are ready without anyone having to transcribe notes.

What monitoring does not promise

The pressurization indicator warns when a room loses its usual pressure relative to the corridor. It is an operational indication, not a normative certification, and it should not be presented as one.

Monitoring detects and records. It does not correct the equipment's temperature: someone has to act, which is why the corrective action is saved. It also does not guarantee, by itself, compliance with a specific standard, and the reports help document what happened. The maps and reports on the site's screens use demonstration data.

When it fits and where to start

It is worth starting with the points where a variation outside the range costs the most or takes longest to be noticed. A few questions help:

1. Who writes down the temperature today, and when? If the answer is a manual round, continuous monitoring fills in the gaps.
2. What happens when the temperature leaves the range at night? The alarm and the e-mail escalation answer that question.
3. Are the calibration certificates under control? The per-sensor expiry warning helps make sure nothing expires unnoticed.