Why is acetone so cold? I have a summer job as a custodian and one cleaner I use is called Goof Off, which is pretty much just acetone. Another is a disinfectant which is mostly water.

Why is it that whenever I put the acetone on my rag, it is always colder than when I use another cleaner or plain water?

The acetone also seems to stay cold longer than water does. Both cleaners are left in the open so they are both the same temperature.
Evaporation is an endothermic phenomenon, i.e. it absorbs heat in order to proceed. Acetone is a volatile solvent (it evaporates easily) so it absorbs much heat when evaporating, and your skin gets colder because of that. That is what you are feeling. So acetone is not "colder", it just cools down your skin more easily when evaporating.

Ether (aka diethyl ether) is even more powerful at this.



On another note, while acetone is a pretty safe solvent, it can damage your skin because it can take away skin's lipids and you get "dry hands". In France, your employer would be forced to provide you with protecting gloves, e.g. latex gloves.