These hot water bottles are used to provide warmth, typically whilst in bed. They are also used for the application of heat to a specific part of the body. Used as a natural body warmer and also for heat therapy treatment. Useful in case of - joint pains, muscular cramps, menstrual pains, muscle pull, stomach and back aches, arthritic and rheumatic pains, bed warmer, sports aches and pains, soothing children and elders.These bags with cover maintains heat for hours. So, It is warm and cosy to cuddle with.