What are the main applicants of latent heat of fusion?
I guess you are asking about application of Latent Heat of Fusion.
Few Applications are:-
1. Put ice in water to cool it down.
2. Water freezing to Ice
3. You can cool off your body by just coming out of a shower or swimming pool if you do not dry off with a towel. It takes 2.3 x 106 J of heat to vaporize 1 kg of water.
4. When steam condenses it releases heat to the surroundings. When just 1 ml of steam water condenses it releases 2.3 x 103J of heat. Then the condensed water cools from 100°C to 37°C (body temperature), so even more heat is released and absorbed by the skin. That's why a steam burn is much worse than a burn from boiling water