Portable heaters at work: controlling fire, electrical and escape-route risks

A reasonable temperature does not justify an unsuitable heater

Employers must provide a reasonable indoor workplace temperature. There is no statutory minimum or maximum, although official guidance suggests at least 16°C for normal indoor work and 13°C where work involves severe physical effort. Portable heating is one possible control, alongside repairing the main system, reducing draughts without losing necessary ventilation, changing work patterns or providing suitable clothing and warm-up breaks.

Start with the cause. A failed radiator, permanently open loading door or poorly balanced heating system usually needs a building or process fix. Repeatedly adding heaters can conceal the problem, increase energy use and load circuits that were never intended to supply several high-wattage appliances.

HSE: workplace temperature ↗ · Related guide: workplace temperature law →

Choose the lower-risk heating method

Fixed central heating or a properly installed fixed convector will usually be easier to control than movable equipment. Where portable heating is necessary, select an appliance designed for the environment, with a stable base, suitable guards and automatic overheat and tip-over cut-outs. Follow the manufacturer’s clearances and operating instructions. Fan and convector heaters are generally preferable to exposed radiant-bar, naked-flame or portable LPG heaters.

Do not let staff bring in unapproved domestic heaters. Keep an approved-equipment list and identify each authorised location. Workshops, dusty areas, temporary structures and places where flammable liquids, gases or combustible dusts may be present need a more specific assessment; an ordinary office heater may be unsuitable even if it looks robust.

GOV.UK: making small non-domestic premises safe from fire ↗ · Related guide: DSEAR risk assessment →

Approve the location and protect escape routes

Place the heater on a firm, level surface where it cannot be knocked over. Maintain the manufacturer’s clearance from paper, curtains, packaging, upholstered furniture, coats and waste. Do not use a heater to dry clothing. Under a desk is rarely a controlled location: feet, bags and trailing coats can contact the appliance, and damage may go unnoticed.

A heater, cable or fuel cylinder must not obstruct a doorway, corridor or final exit. It must not reduce the clear width of an escape route or tempt people to wedge a fire door open. Consider foreseeable movement of trolleys, visitors and stock, not just the tidy arrangement seen during an assessment.

People who may not recognise heat or smoke, move away quickly or evacuate without help need additional controls. In care, clinical, education or sleeping accommodation, a safer fixed solution, restricted access, closer supervision and person-centred evacuation arrangements may be necessary because the consequences of a small mistake are greater.

GOV.UK: fire risk assessment for offices and shops ↗ · Related guide: workplace fire evacuation plans →

Check the electrical load, not only the PAT label

Before use, confirm that the heater is suitable for the supply and that the circuit can carry the expected load. High-powered heaters can overload adaptors, extension leads or circuits already serving other equipment. Connect the appliance only in accordance with the manufacturer’s instructions and a competent electrical assessment; if capacity is uncertain, obtain advice from a competent electrician.

Users should check the plug, cable, casing, controls and ventilation openings before use. Remove the appliance from service if there are scorch marks, a loose plug, exposed wires, damaged insulation, unusual noise or smell, or if the cable has been trapped or stretched. Do not bunch or coil a cable where heat can build up, and do not create a trip hazard.

Portable appliance testing is not a certificate that makes a heater safe until the next sticker date. HSE requires maintenance to be proportionate to the risk, using user checks, formal visual inspection and electrical testing where appropriate. Frequency depends on the equipment, environment and use rather than a universal annual interval.

HSE: work using electrically powered equipment ↗ · HSE: maintaining portable electrical equipment ↗ · Related guide: PAT testing at work → · Related guide: electrical installation inspection →

Control use, shutdown and fuelled heaters

Name the people authorised to approve, move and isolate heaters. Give users simple rules: never cover the appliance; keep the required clearance; do not leave it running in an empty room unless it is specifically designed and assessed for that purpose; switch off and unplug safely at the agreed time; and report defects immediately. Cleaning and stock movements should not quietly change the approved arrangement.

Portable LPG, paraffin and other fuel-burning heaters create additional fire, fuel-storage, ventilation and combustion-product risks. Government guidance says LPG heating in public areas should be exceptional and specifically risk assessed. Where a dangerous substance is involved, assess the DSEAR duties as well as fire safety. A fuelled heater should not be treated as a convenient substitute for a failed fixed system.

GOV.UK: fire risk assessment for small and medium places of assembly ↗ · Related guide: fire extinguisher checks →

Review and update the fire risk assessment

The Regulatory Reform (Fire Safety) Order requires a suitable and sufficient fire risk assessment and requires it to be kept up to date. Introducing portable heaters, changing their type or moving them into new areas can change ignition sources, people at risk and escape conditions. That is a reason to review the statutory fire risk assessment rather than simply adding a local rule.

If the existing assessment does not adequately cover the new hazard, complete a linked portable-heater assessment. Record the approved appliances and locations, electrical capacity, combustible clearances, vulnerable occupants, inspection regime, supervision, shutdown arrangements and emergency actions. Incorporate its findings into the main fire risk assessment, emergency arrangements, training and physical controls so it does not become an isolated form that nobody applies.

Fire Safety Order 2005, articles 8 and 9 ↗ · HSE: introduction to fire safety ↗

Portable heater workplace checklist

Legal requirements and official guidance were checked on 30 October 2026. The practical test is whether the heater remains safe in everyday use, not whether it looked acceptable on the day it arrived.

• Identify and correct the underlying cause of the cold area where reasonably practicable.
• Approve the heater type, wattage and intended location before use.
• Prefer fixed or enclosed convector heating to exposed radiant or fuel-burning equipment.
• Confirm the appliance suits the environment and electrical supply.
• Keep the heater clear of paper, packaging, clothing, furniture and waste.
• Keep appliances, cables and cylinders out of circulation areas and escape routes.
• Check the plug, cable, casing, controls and vents before use.
• Remove defective, scorched, unstable or unauthorised equipment immediately.
• Set rules for moving, supervision, cleaning and end-of-day shutdown.
• Plan additional protection and evacuation support for vulnerable occupants.
• Complete a DSEAR assessment where fuels or other dangerous substances are relevant.
• Review the fire risk assessment and incorporate any linked assessment findings.