Answer :
first milk is heated to a high temperature and then cooled quickly because of which the germs are killed hence making milk safe to drink.
The process in which milk is heated to about 70 degrees Celsius for 15 to 30 seconds and then suddenly chilled and stored is called pasteurization. This process was discovered by Louis Pasteur. Pasteurization milk can be consumed without boiling as it is free from harmful microbes.