An overheat detection system and insulation muff comprising an overheat detection system. The overheat detection system comprises a thermometer, a thermal harvesting module comprising at least one passive radiator, the thermal harvesting module being able to generate electrical energy from the thermal difference between two elements, and a digital module, comprising a power management system, a data treatment system and a wireless transmission system, wherein the electrical energy generated by the thermal harvesting module powers the thermometer and the digital module.