Drivers have been issued a stark warning over the common car issue – but there’s an easy way to tackle it
Motorists have been warned that demisting your car is key, and you cannot set off without doing this, as it’s illegal. This is because it can “impede your vision while driving”, which is against the law, and can cause a number of other issues.
Experts at RAC Drive explained how this can happen. It said: “The cause of your car windscreen misting up is actually down to water vapour in the atmosphere that occurs when your body heats the air inside the cabin – as does your breath – increasing the amount of moisture it can hold.”
However, there is a simple method that can “clear your windscreen in double-quick time”. All you need to do is use your heater – and here’s how.
Demist your car in minutes – step by step
METHOD ONE
- Start the heater off cold, then slowly increase the temperature as the air dries out, rather than overloading the cabin with hot, ‘wet’ air
- Try to find a temperature and humidity that’s comfortable but doesn’t mist up the cabin
- Make sure your heater’s blast is directed at the windscreen and the windows – the warmer air (even on cold the air will be warmer than the ice cold windscreen) will dry the glass a little through evaporation and begin to heat up the glass to stop the water vapour condensing on it again.
If you are cold, they suggest pointing the hot air towards the windows and yourself. Although this may take longer, you’ll stay cosy. RAC Drive reminded people that if they do this, “just don’t move off until all glass surfaces on your car are clear. It’s dangerous and illegal if visibility is impeded”.
METHOD TWO
If your car has air conditioning, switch it on and use it in conjunction with the heater. The experts explained that the “hot air will dry the glass a little through evaporation, but the air will then cool down and condense on the glass once more, so make sure the air-con is on to keep the atmosphere inside dry”.
METHOD THREE
If your car doesn’t have an advanced climate control system, opening the windows can help clear the windscreen quickly. Letting in the cold, dry outside air helps reduce the amount of moisture inside the car, preventing the windows from misting up. Once the windscreen is clear, you can gradually warm up the car to a comfortable temperature.
If your windows start to mist while you’re on the move, this is a useful trick for vehicles without air conditioning. If the misting becomes severe and affects your visibility, pull over safely and wait until your windows have cleared before continuing, RAC suggested.
Prevent this from happening by doing this
Keeping your windscreen clean is one of the best ways to prevent it from misting up in the first place. For an extra layer of protection, try cleaning it with shaving foam. The thin film it leaves behind acts as a temporary barrier that helps stop condensation from forming. RAC states that it will need to be reapplied periodically and in fact, it’s the same clever trick ice hockey players use to keep their visors from steaming up on the ice.
If you want to do this, follow these steps:
- Take a clean towel and place a dollop of shaving foam onto it
- Wipe the windscreen with the towel, spreading the shaving foam over the entire surface
- Take another clean towel and wipe off the shaving foam completely
My car is not demisting
If your car isn’t demisting properly, there could be several possible reasons why. The most common is with the air conditioning or temperature control. The best first step is to set the heater to its highest setting and direct the airflow towards the windscreen.
Ensure the air conditioning is turned on and the air recirculation setting is set to off. If this still doesn’t solve the problem, it’s best to take your car to a trusted local garage or call a mechanic.
RAC Drive conclude: “They will need to check for airflow and filter issues – as well as if there are any blockages in the vents. Other problems include a broken heater or internal thermostat. In other cases, it may just need coolant added to the system.”

















































