Winter electrical safety at work: portable heaters, extension leads and battery chargers

Portable heaters, extra extension leads and battery chargers can change how a workplace uses electricity during winter. A short review before seasonal equipment returns to use helps you spot damage, agree safe locations and plan any inspection or testing needed.

Agree how heaters will be used

• Approve the equipment and its location through your site arrangements, including heaters brought in by staff.
• Follow the manufacturer’s instructions. Keep heaters stable, uncovered and clear of paper, furniture and escape routes.
• Plug portable heaters directly into a suitable wall socket, rather than an extension lead or multi-way adaptor.
• Switch heaters off when unattended and at the end of the working day.

Electrical Safety First recommends keeping portable heaters at least a metre from combustible materials. Follow any greater clearance specified for the product. See its portable-heater advice.

Several wall sockets may share a circuit. If additional heating raises questions about supply capacity, ask a competent electrician to assess it; moving a plug does not establish that the circuit can carry the load.

Check extension leads and reels

Read the rating on the actual lead or reel and consider the combined load of the connected equipment. Do not assume every extension is rated at 13A. Avoid connecting one extension to another, keep cables protected from crushing and fully unwind cable reels before use.

Stop using equipment with damaged insulation, loose fittings or signs of overheating. A surge protector does not make an overloaded extension safe. Electrical Safety First provides guidance on extension leads, reels and adaptors.

Make charging arrangements clear

Use the charger supplied with the battery or one recommended by its manufacturer. Keep charging areas ventilated and away from escape routes and combustible materials. Do not use or charge a damaged or swollen battery.

E-bikes, e-scooters and tool batteries need a suitable workplace policy and risk assessment. The London Fire Brigade’s charging guidance covers charger compatibility, charging locations and supervision.

If a battery is smoking, hissing or showing signs of fire, raise the alarm, leave the area and call 999. Do not attempt to move a failing battery through the building. A PAT pass is not a battery-condition or fire-safety guarantee.

Bring stored equipment back into use carefully

Check heaters, leads and chargers for damage before they return to service. Include the plug, cable, enclosure and any signs of damp or contamination. Follow the manufacturer’s storage, cleaning and operating instructions; do not open electrical equipment to clean or repair internal parts.

Equipment moved from cold storage may need time to reach suitable operating conditions. Follow its instructions and obtain competent advice if there is moisture or uncertainty. There is no single waiting time that makes every damp appliance safe.

Deal with workplace temperature at its source

Review persistent cold areas with the person responsible for the building rather than allowing an unplanned collection of heaters. HSE’s guidance describes a reasonable indoor temperature and normally suggests at least 16°C, or 13°C where work involves rigorous physical effort. These are guidance values, not a universal statutory minimum.

Read HSE’s workplace temperature guidance for the context and applicable exceptions. A PAT visit does not assess whether the building’s heating provision or workplace temperature is adequate.

Use a practical winter equipment checklist

• List seasonal equipment and agree who is responsible for it.
• Inspect stored items before use and report damage immediately.
• Agree heater locations, charging areas and end-of-day checks.
• Review the maintenance plan using the equipment’s use, environment and previous findings.
• Record faults, remove unsafe items from use and arrange appropriate repairs or replacement.

Set inspection and testing intervals around the risk rather than adding a blanket annual or mid-winter test. Our frequency guide explains the approach.

Plan the PAT testing part of your winter checks

For an AiO quotation, send your postcode, equipment list or approximate count, and any access or shutdown restrictions. Mention industrial connections, inaccessible equipment and more than one site before booking.

Get your PAT testing quote or speak to AiO about a planned visit. You can also see our report and label examples.