Solar backpacks are generally safe to use and have built-in safety features to prevent overheating. The solar panels are designed to efficiently convert sunlight into energy without reaching temperatures that could cause overheating. However, it is important to follow the manufacturer’s instructions for proper use and maintenance to ensure safe operation. As with any electronic device, it is advisable to avoid exposing the solar panels to extreme heat or prolonged direct sunlight, which could potentially lead to overheating issues.