Ever seen a glassblowing demonstration? There's blistering heat, molten glass and a hollow tube used to blow air into the volcanic glob. Oh yeah, and it's almost always a demonstration performed by an adult -- unless, of course, you were a child of the 1950s who was given a Gilbert Glass Blowing Set.
Luckily, the set contained a detailed instruction manual. The downside is that it spelled out ways to heat the glass to a malleable state, which is 1,000 degrees Fahrenheit (538 degrees Celsius), and then encouraged children to conduct dangerous experiments without the use of safety equipment. Although we seriously doubt cheap plastic glasses would have been much protection if a budding craftsman had completed one of the experiments that required inflating a bubble of hot gas until it burst [source: Young].