May contain traces of nut
Going/been to Bristol to see all the Grommits?
I was there on the day. Later in the afternoon, the fire chief took us upstairs to an office adjoining the bit the burnt down and opened a connecting door. It was truly astounding seeing the mess and how the girders of the building had just twisted and collapsed like they were made of plastic.Not long after our visit, there was a major fire in the warehouse and several items and sets were destroyed. Heat and plasticine are not happy bedfellows.
I think you mean that it loses its ductility/fracture toughness and becomes prone to brittle fracture. (The tensile strength actually increases as you reduce the temperature see for instance http://www.keytometals.com/page.aspx?ID=CheckArticle&site=kts&NM=48)Steel loses its strength at a remarkably low temperature.