The crossword solution for the term 'LAB HEATER OF OLD' is ETNA. Etna is an active stratovolcano on the east coast of Sicily, Italy. It is the highest active volcano in Europe and one of the most active in the world. Etna has been erupting for thousands of years and is known for its frequent and sometimes violent eruptions. It is also a popular tourist destination due to its spectacular views and unique geological features.