You can find this Frost King water heater insulation blanket at Amazon. However, it's important to follow the manufacturer's instructions carefully to avoid covering essential controls and vents.

We've crunched the energy cost numbers and compared the pros and cons of hot water bottles, electric blankets and heated throws ... Why you shouldn't use an electric heater while you sleep Electric ...

That's as long as you only boil as much water ... blankets is fitted below your bedsheet, you won't even know it's there, and it will gently spread warmth throughout your bed for as long as you need ...