How should the hot water bottle be filled, and how long does it stay warm?

Fill the hot water bottle with warm or moderately hot water — not boiling water. Water that is too hot speeds up wear of the rubber and creates a risk of burns on contact with the skin. The label does not state a specific water temperature: aim for warmth that feels comfortable and does not scald.

How to fill it: lay the hot water bottle on a flat surface, carefully open the stopper and pour in water to about two-thirds of its capacity. Before closing it, let the air out — gently squeeze the body so that the water rises to the neck, then screw the stopper on tightly. This reduces the pressure inside and lowers the risk of leaks.

The label does not state how long it retains heat: this depends on the starting temperature of the water and the conditions of use. If you keep the hot water bottle under a blanket or wrap it in a towel, the warmth lasts longer.

After use, pour out the water, leave the stopper slightly loosened and store the hot water bottle laid flat in a cool place out of direct sunlight — this extends the life of the rubber.