Clash81, this isen't true. Windshilelds neither can break due to heat nor due to massive rain! What ever you said About heater is 0% true. Our Fiat's heater have timer. Although you switch it on it'll switch off itself after 20mins. So heater cracked windshield makes no sense. Mhitesh, this might have happened due to wiper. Some one might have pulled & pushed your wiper making a harder impact. I'll suggest get it done from ''Windshield Experts''. Those people are very professional in their work.