Miguel bought a new fish for his fish tank. He brought the fish home in a plastic bag that was filled with water from the fish tank at the store. Before releasing the fish, he put the entire bag into his tank so the fish could get used to the temperature of the water in his tank at home. Miguel explains to his sister that heat is transferring from the water in the tank to the water in the bag. Miguel’s sister doesn’t believe him because the water in the tank doesn’t feel hot. Temperature of the water in his home tank: 21 C
Temperature of the water in the bag: 18 C

How is it possible that heat is transferring from the water in the tank to the water in the bag, even though the water in the tank doesn’t feel hot?