UK drivers warned of fines for car heater mistake in winter: what you can actually be fined for

What the headlines say

On 19 October 2026 regional papers, including the Slough Observer, ran the headline “UK drivers warned of fines for car heater mistake in winter”. The warning came from the car insurer Tiger.co.uk. Its point is that running the heater hard for a long time, especially with the air recirculating, makes the cabin warm and stuffy and can make a driver drowsy.

The articles say drivers who blast their heaters risk penalty points and an unlimited fine. That is the part that needs unpicking.

Is there a fine for the heater? No

There is no offence of using your car heater, however high it is turned up, and no rule in the Highway Code about heater settings.

The penalties in the story belong to careless and dangerous driving, which apply however a driver came to be tired. Careless driving carries 3 to 9 penalty points; for lower-level cases the police can offer a £100 fixed penalty with 3 points instead, and in England and Wales a court can impose an unlimited fine. Dangerous driving carries 3 to 11 points if the court does not disqualify the driver. Nobody is fined for the heater itself; a driver could be prosecuted for driving badly because they were too tired to drive safely.

The Highway Code's rule on tiredness, rule 91, says driving when you are tired greatly increases the risk of a collision. It recommends a break of at least 15 minutes after every two hours of driving, and says to stop somewhere safe if you feel sleepy, though not on a motorway hard shoulder.

The sensible part of the advice

The insurer's practical tips are reasonable on their own terms: keep the cabin comfortable rather than hot, around 19 to 22°C in its suggestion, let fresh air in rather than recirculating the same air for long stretches, and crack a window or take a break if you feel drowsy on a long journey.

The winter fines that do exist

Leaving the engine running. Highway Code rule 123 says you must not leave a vehicle's engine running unnecessarily while it is stationary on a public road. Councils in England and Scotland can issue a £20 fixed penalty for needless idling, rising to £40 if unpaid. In Wales, from 30 September 2026, councils set their own penalty of between £75 and £150. Police can also treat it as an offence with a £50 fixed penalty, or a fine of up to £1,000 for a car in court.

Driving before the glass is clear. Rule 229 says you must be able to see, so clear all snow and ice from all your windows. The law behind it requires glass that does not obscure the driver's view, and breaking it can mean a fine of up to £1,000 for a car in court. Number plates must be clearly visible too: an obscured plate is a separate offence, also with a fine of up to £1,000.

This is where the heater genuinely matters: use it, with the fan on the windscreen, to clear mist and ice properly before you set off, and stay with the car while you do. Our guide to leaving your car running to defrost sets out where the line is, and what happens with your insurance if a car is stolen while it defrosts.

What to do

Use the heater to clear the windows and keep yourself comfortable, not hot. On a long drive, let fresh air in and take a 15-minute break every two hours. Before you set off on a frosty morning, clear every window and the number plates completely, not just a hole in the windscreen. Our car emergency kit checklist covers what to keep in the boot for winter, from a scraper and de-icer to a blanket and a phone charger.