This pack of quick heating boyz toys hand warmers is individually wrapped with 2 hand warmers the perfect winter essential these innovative hand warming devices create instant heat and can keep your extremities comfortably warm for up to 7 hours these hand warmers are incredibly safe to use and are disposable so there is no need to worry about chemicals or waste the heat is based on the oxidisation of iron the warmers safely utilise heat released during the natural reaction of iron rustin