Plug in for 15 minutes and enjoy the pain relief from hot water up to 5 hours. This innovative solution allows the water to say hot longer: it is more convenient to use. You don’t need to pour boiling water, to refill water like with classical water bottle. No microwave. Safer to use; No wires, no mess, the device is supplied with an auto-shutoff thermostat. Stay warm during these cold nights. Could also be used outdoor at the stadium, fishing, Ski or for people working in the cold for hours. Warm water help to alleviate pain, aches and to relieve stress and muscles. Rechargeable: red light indicates when fully charged. UL Approved. Don’t use while plugged in.