Overview
- RAC advice says never pour boiling water on icy windows because thermal shock can crack the glass and lead to costly repairs.
- The group recommends a low-cost anti-fog step: put a small amount of shaving foam on a towel, spread it over the windscreen, then wipe it off to leave a temporary barrier.
- The anti-fog effect is not permanent and should be reapplied as needed alongside routine cleaning and proper ventilation to reduce misting.
- Drivers are urged to prepare by using an overnight windscreen cover or a dry towel, keeping a scraper and de-icer in the car, and allowing about 10 minutes to clear visibility before setting off.
- The AA advises additional prevention such as parking in a garage, positioning the car close to the house for residual warmth, or securing thick cardboard across the windscreen.