A refrigerant pack is provided with a refrigerant substance containing water, a precipitating component, a non-precipitating component, and a pH indicator, and is configured such that the precipitating component precipitates when the refrigerant substance freezes and is a component not corresponding to the pH indicator, the non-precipitating component does not precipitate when the refrigerant substance freezes and is a component not corresponding to the pH indicator, a change or the presence/absence of coloring in the pH indicator is reflected before and after freezing, and the refrigerant substance changes in color.