Thick Glass tumbler-- breaks when hot liquid is poured in

When you pour boiling liquid in a glass tumbler it bursts or cracks. The reason behind is as follows:

When hot liquid is poured, the thick glass tumbler breaks because the inner surface of the glass expands due to heat but the outer surface remains comparatively cool. Due to this unequal expansion, the thick glass tumbler breaks.
Never pour boiling liquid in glass vessels…