Pilots in the First World War had to fly at high altitudes and high speed therefore it would be extremely cold so to prevent them from freezing they not only have to put on many layers but they must also put on some whale oil. This was essential to the war because without it they would either have no planes in the sky or every pilot that went up came back down with more than just a cold meaning nobody would dare to go up into the skies without any planes we surely would have lost the war because they went just for dog fights they could also be used to drop bombs in enemy territory and for spying on the enemy. This may not be a daily use but is used for every trip that is why it was needed in the great war.
