Athletic trainers use instant ice packs that can be cooled quickly on demand. squeezing the pack breaks an inner container, allowing two components to mix and react. this reaction makes the pack become cold. describe the heat flow for this spontaneous process.

The heat flow is  best described as an exchange of heat between the system and the surroundings.

Explanation:

Heat is a form of energy which is transferred spontaneously from a hotter body to a cool body as a result of temperature differences between the substances. In the problem , it can be said that heat moves from  the surroundings which may be a fractured knee of the athlete to the ice packs.