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uk Transport & mobility emergencies

What to do if…
your vehicle shows an overheating warning or starts producing steam or light smoke

Produced and maintained by PanicStation.org Published: Last reviewed: Editorial policy UK guide

Short answer

Move out of traffic as safely as possible, stop and switch the vehicle off. If there are flames, increasing smoke or another sign of fire, get everyone away from the vehicle and call 999.

Do not do these things

  • Do not continue driving to see whether the warning clears.
  • Do not remove the radiator or coolant filler cap while the engine is hot.
  • Do not touch escaping steam, leaking fluid or hot components.
  • Do not open the bonnet if you suspect a fire in the engine compartment.
  • Do not attempt to extinguish a fire in the engine compartment.
  • Do not stand between the vehicle and moving traffic.
  • Do not place a warning triangle on a motorway.
  • Do not repeatedly restart the vehicle or assume it is safe because the warning has disappeared.

What to do now

  1. Ease off the accelerator, signal and move to the nearest place of relative safety. On a motorway, leave at the next exit or enter a service area if possible; otherwise move left into an emergency area or onto the hard shoulder.
  2. Stop as far from moving traffic as possible, apply the parking brake, switch on the hazard warning lights and switch the vehicle off. On a motorway hard shoulder or emergency area, turn the wheels to the left.
  3. If there are flames, increasing smoke, crackling sounds or a strong burning smell, get everyone out using the side furthest from traffic when it is safe. Move well away from the vehicle, preferably behind a safety barrier, and call 999 for the fire and rescue service.
  4. If you are stopped in a live motorway lane and there is no active fire, leave the vehicle only if you can reach a safer place without entering moving traffic. If you cannot exit safely, stay inside with seat belts and hazard warning lights on and call 999 for the police.
  5. If there are no signs of fire, wait well away from traffic while the engine cools naturally. Do not open the coolant filler cap until the engine is completely cold.
  6. Contact a breakdown recovery service and describe the overheating warning, steam, smoke, smells, leaks and any loss of power. Give your exact location and say if anyone is unable to leave the vehicle safely.
  7. Follow the vehicle handbook and the recovery provider’s instructions. Do not restart or continue the journey while steam, smoke, leaking fluid, an unusual smell or an overheating warning remains.

What can wait

You do not need to diagnose the fault, choose a repair, rearrange the whole journey or decide whether to replace the vehicle now. Garage comparisons, insurance questions, warranty checks and longer-term travel plans can wait until everyone and the vehicle are safely away from traffic.

Important reassurance

An overheating warning does not necessarily mean the vehicle is on fire, but steam and smoke can be difficult to distinguish. Stopping early, switching the vehicle off and keeping a safe distance are sensible actions while the cause is unknown.

Scope note

This guide covers immediate safety and stabilisation only. Diagnosis, repair and any decision to drive the vehicle again may require roadside assistance or a qualified mechanic.

Important note

This is general road-safety information and is not a substitute for vehicle-specific instructions or professional assessment. Follow the vehicle handbook and any instructions from the emergency services, the relevant road operator or your recovery provider.

Additional Resources

Closely connected guides that may be useful during the same situation or its immediate aftermath.

About this guide

This guide was produced and is maintained by PanicStation.org using its published editorial process. Official and specialist sources are checked where relevant, and AI-assisted tools may be used for drafting, organisation, and consistency checks. The site operator remains responsible for publication, revision, and removal decisions.

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