Use advanced insulation to prolong the cooling time. In the case of no damage and normal maintenance, the temperature bag can be pre-cooled for several thousand times or more; the constant constant temperature is maintained at an external temperature of 90 degrees Fahrenheit. 6 hours of contact temperature of 14~20 °C. It consists of a vest, a cold storage bag and a cold plate. Uses: Suitable for heatstroke prevention and cooling under high temperature, high heat and high humidity environment, such as metallurgy, casting, glass, fire, cook, etc., the quality is 1.865kg, the contact temperature is 5.4°C, and the temperature of the coolant is 298.2KJ/kg.