Measuring your body temperature with a glass thermometer is pretty handy, but making the instruments is not easy.

A finished mercury-in-glass thermometer requires at least 25 intricate steps including blending the mercury bulb, crafting the neck of the tube and narrowing the throat.

Sadly, such thermometers may soon be phased out as the World Health Organization has slated to ban them for medical use by 2020 due to the toxicity of mercury. Some manufacturers have thereforestarted to use galinstan, a liquid alloy of gallium, indium, and tin, as a replacement for mercury.

Before they go, let's take a quick look at how to make a glass thermometer at a medical equipment manufacturer in Yancheng, Jiangsu province.

A woman presents finished glass thermometers at Jiangsu Yuyue Medical Equipment & Supply Co Ltd in Jiangsu province on Feb 3. [Photo / IC]