Frozen windscreen: four things that ruin it faster than a stone

The glass in a car is not one piece. A windscreen is laminated, two panes with a film between them, and each of those layers expands differently when the temperature changes. That difference is where the cracks come from, the ones drivers manage to create themselves in thirty seconds.

Hot water from the kettle. The classic we still see every winter. An eighty-degree gap between the water and the glass creates stress the glass cannot take even when it is perfectly healthy. If there is already a small chip in it, the crack starts instantly and usually runs the full width.

Heater on full the moment you start the engine. The same problem, only slower. Point hot air at frozen glass at full power and you are warming it from the inside while the outside stays below zero. Start on the lowest setting and bring the temperature up gradually. It costs you three extra minutes and nothing else.

A sharp or metal scraper. It will not crack the glass, but it leaves fine grooves that scatter the headlights of oncoming cars at night. Two years later you wonder why every car dazzles you. A plastic scraper with a straight edge costs next to nothing and lasts for years.

Wipers switched on while the blades are frozen down. The wiper motor does not try to be gentle, it pulls until something gives. That something is either the wiper rubber or the gearbox of the mechanism. If you parked with the wipers switched on and they are frozen down in the morning, free them by hand first.

What does work: de-icer spray, a plastic scraper, a cover over the windscreen overnight and a little patience. And if there is already damage on the glass, do not take it into winter. Frost will turn it into a crack more reliably than anything else.