In the event of specific heating or cooling of a glass surface, thermal stress creates tension and causes the glass to break.
There are many causes: solar radiation on part of the glazing (partially lowered blind) or shade from the building, presence of a radiator, paint or a sheet glued to the glass, presence of a dark sofa less than 30 cm from the glazing, dark curtain partially closed, etc. Thermal shock failures are common but are not covered by factory warranties.
In the event of breakage by impact, the analysis of the slit will determine the type of stress; a thermal shock being characterized by a slit perpendicular to the edge of the glass and starting at 90° on the face, then in branching.
We recommend the use of tempered glass when high thermal stresses are expected.