A water bath is a laboratory equipment made from a container filled with heated water. It is used to incubate samples in water at a constant temperature over a long period of time.

An oil bath is a laboratory equipment made from a container filled with heated oil. It is used to incubate samples in oil at a constant temperature over a long period of time.  

A sand bath is a laboratory equipment made from a container filled with heated sand. It is used to incubate samples in sand at a constant temperature over a long period of time.