1. A temperature monitoring device for an injection molding machine with a heating cylinder covered by an openable shield,
the temperature monitoring device comprising:
a heating unit configured to heat the heating cylinder;
a detecting unit configured to detect a current temperature of or around the heating cylinder;
a storage unit configured to store a prohibited temperature at which the shield is prohibited from opening; and
a prohibition unit configured to prohibit the shield covering the heating cylinder from opening if the detected current temperature
exceeds the prohibited temperature.