Cambridge Secondary (7-9). Stage 8. Science. Learner's Book - Unit 8: Chemical reactions - Question 43

One type of ice pack is stored in a fridge or freezer; the ice melts as it cools an injured area, and the pack can be frozen again. Another type has separate compartments, usually containing ammonium nitrate and water. Breaking the divider lets them mix; dissolving absorbs thermal energy and the pack cools without a freezer.

Describe one advantage and one disadvantage of each of the two types of ice packs described above.