“Heat Soak Test” – spontaneous cracking of tempered glazing cannot be ruled out. excluded. In order to maintain the stability of the structure and its components, both internal and external, and the safety of users, the consequences of this risk should always be considered. The risk of self-breaking glass can be significantly reduced by using additional heat treatment of tempered glass called “Heat Soak Test”. This process involves placing glass elements in the furnace and subjecting them to specific temperatures.