The Reid wrote:
Following up to Paul Andrews
I wouldn't risk it. [hot water to defrost windscreen] I've never
seen why people just don't clear thewindscreen as I do - with a
credit card..

or a £1.50 scraper you keep in the door pocket?

69p from Lidl.

The disadvantage with these scrapers is that they have straight
edges, .: aren't so good for windscreens. Credit cards, and so
on, are much better as long as the ice isn't too thick.

A pail of water from the cold tap is quick and efficient.