How-To Guide

How to Set Up Temperature Monitoring in Your Food Business

Complete guide to temperature monitoring for UK food businesses. Covers what to monitor, equipment selection, recording systems, critical limits, and corrective actions.

Estimated time: 2 hours

Temperature control is the single most important factor in preventing bacterial food poisoning. Bacteria that cause food poisoning (such as Salmonella, E. coli O157, Listeria, and Campylobacter) multiply rapidly in the danger zone between 8°C and 63°C, and can double in number every 20 minutes under ideal conditions. Effective temperature monitoring is not just about having a thermometer — it is about having a systematic approach to checking, recording, and acting on temperature data across your entire operation.

Under UK food safety legislation, food businesses must have procedures in place to maintain the cold chain and ensure that food is cooked, cooled, and stored at safe temperatures. Your EHO inspector will check your temperature monitoring system and records, and inadequate temperature control is one of the most common reasons for low food hygiene ratings.

This guide covers how to set up a complete temperature monitoring system, from identifying what needs to be monitored through to calibrating equipment and defining corrective actions for temperature breaches.

7 steps to complete

1

Identify everything that needs temperature monitoring

Map out every point in your operation where temperature is critical to food safety. This includes all fridges and freezers, deliveries on arrival, cooking and reheating processes, hot-holding equipment (bains-marie, heated counters, soup kettles), cold-holding and display units, cooling processes, and any transport or delivery of temperature-controlled food. Create a list of every piece of cold or hot storage equipment with its location and what it stores.

2

Choose appropriate monitoring equipment

Invest in a calibrated digital probe thermometer for checking food core temperatures — this is essential for cooking, reheating, and delivery checks. For fridges and freezers, you can use the built-in digital display (if accurate) or a separate fridge/freezer thermometer placed in the warmest part of the unit. Consider infrared (non-contact) thermometers for quick surface checks, but remember these only measure surface temperature and cannot replace probe checks for core temperature. All thermometers should be food-grade and capable of reading in the range -50°C to +150°C.

3

Set monitoring frequency for each check point

Define how often each temperature check must be done. Fridge and freezer temperatures should be checked and recorded at least twice daily (opening and closing). Cooking temperatures must be probed for every batch at the thickest point. Delivery temperatures should be checked on arrival for every chilled or frozen delivery. Hot-holding temperatures should be checked every two hours during service. Cooling should be monitored at intervals to ensure food passes through the danger zone within the required time. Document the monitoring frequency for each check point in your SFBB or HACCP plan.

4

Establish critical limits for each monitoring point

Set clear, non-negotiable temperature limits based on UK food safety guidelines. Fridges must operate between 0°C and 5°C (ideally 1°C–4°C). Freezers must be at -18°C or below. Cooking must achieve a core temperature of at least 75°C (or 70°C held for 2 minutes). Hot holding must remain at 63°C or above. Food being cooled must pass from 63°C to below 8°C within 90 minutes. Chilled deliveries should arrive at 8°C or below (ideally 5°C or below). Frozen deliveries should arrive at -15°C or below.

5

Create a recording system

Set up a structured system for recording all temperature checks. Whether you use paper log sheets or a digital system, each record must include the date and time, the equipment or food item checked, the temperature reading, the name or initials of the person taking the reading, and any corrective action taken if the temperature was outside limits. Organise records by area (fridge log, cooking log, delivery log) and keep them filed chronologically. Incomplete or missing records are treated the same as no monitoring by inspectors.

6

Define corrective actions for temperature breaches

Document exactly what staff must do when a temperature reading falls outside critical limits. For a fridge above 8°C: check door seal, move food to a working unit, check if food is still safe (under 2 hours above 8°C is generally acceptable; over 4 hours means dispose), and arrange repair. For undercooked food: continue cooking until the correct core temperature is reached. For hot-held food below 63°C: reheat to 75°C or discard if it has been below 63°C for more than 2 hours. All corrective actions must be recorded alongside the temperature reading.

7

Calibrate equipment regularly

Thermometer accuracy drifts over time and with use. Calibrate probe thermometers at least monthly using the ice point method (a glass filled with crushed ice and a small amount of water should read 0°C ±0.5°C) or a verified calibration thermometer. Record calibration dates and results. If a thermometer is inaccurate by more than 1°C, replace it. Check fridge and freezer thermometers against a known-accurate probe thermometer quarterly. Using an inaccurate thermometer is worse than having no thermometer — it gives false confidence.

Tips for success

Keep probe thermometer wipes next to the thermometer. Probing raw chicken and then probing a dessert without cleaning causes cross-contamination. Anti-bacterial probe wipes are cheap and essential.
Set fridge temperatures to 3°C rather than 5°C. This gives you a buffer — if the temperature rises slightly during a busy service with frequent door openings, you remain within the safe range.
Place fridge thermometers in the warmest part of the unit (usually the door shelf or top shelf, away from the cooling element). A reading from the coldest spot does not tell you whether all food in the fridge is safe.
Use a digital temperature monitoring system that sends alerts when temperatures exceed limits. This catches problems outside of manual check times, such as a fridge failure overnight.
Label your probe thermometer with a unique ID and reference it in your calibration records. If you have multiple thermometers, you need to know which one was calibrated when.

Common mistakes to avoid

Relying solely on fridge display temperatures without verification
Built-in fridge displays measure air temperature near the sensor, which may not reflect the temperature of food in other parts of the unit. Regularly verify the display reading against a calibrated probe thermometer placed in a glass of water inside the fridge. This gives a more accurate representation of food temperature.
Recording temperatures but not acting on out-of-range readings
A temperature log that shows repeated readings of 9°C with no corrective action is worse than no log at all — it proves you knew there was a problem and did nothing. Every out-of-range reading must have a documented corrective action.
Only probing food temperatures for inspections, not routinely
Cooking temperatures must be probed routinely for every batch, not just when you expect an inspector. Consistent probing is the only way to verify that your cooking process reliably achieves safe temperatures. Make it a non-negotiable part of the cooking workflow.

Frequently asked questions

How often do I need to check fridge temperatures?

At minimum, check and record fridge temperatures twice daily: once at the start of the day and once at the end. Many businesses check three times daily (morning, midday, evening) for added assurance. The key is consistency — whatever frequency you set must be followed without gaps. Digital monitoring systems that log temperatures continuously provide the best evidence, but manual checks twice daily meet the basic requirement.

What probe thermometer should I buy?

Choose a digital probe thermometer that is food-grade, has a thin probe tip for fast readings, reads in the range -50°C to +150°C, and has an accuracy of at least ±0.5°C. The probe should be waterproof and easy to clean. Reputable brands include ETI, Comark, and Thermapen. Expect to pay £20–£70 for a good-quality thermometer. Avoid cheap unbranded thermometers as they tend to lose accuracy quickly.

Do I need temperature records for every single dish I cook?

You need to be able to demonstrate that your cooking processes consistently achieve safe temperatures. For high-risk items (poultry, reheated food, minced meat), probing every batch is strongly recommended. For standardised processes (e.g., frying chips at a set temperature and time), you can verify the process periodically and record it, rather than probing every single portion. However, any change to the process (new equipment, different portion size) requires re-verification.

What should I do if my fridge breaks down overnight?

If you discover a fridge failure, immediately check the temperature of the food inside using a probe thermometer. If food is still at 8°C or below, transfer it to a working unit immediately. If food has been above 8°C for an unknown period (you cannot determine how long), it should be disposed of as a precaution. Record the incident, the action taken, and arrange repair or replacement. Check your food safety insurance policy, as some cover stock loss from equipment failure.

Ready to simplify compliance?

Paddl automates the processes described in this guide. Digital records, automatic alerts, and complete audit trails for your hospitality business.

Full access to all features · Dedicated onboarding support · Cancel anytime