When we refer to a hot water bottle, the English word is "hot water bottle" rather than "hot water bag".

First of all, in order to ensure the safety and comfort of users, the sealing and structural rationality of the hot water bottle are crucial. The word "bottle" more appropriately describes the essence of a hot water bottle: storing and transporting liquid, similar to the function and structure of a bottle. The bottle must have a complete seal to contain high-temperature liquids, and at the same time, it must be able to safely contact human skin and provide warmth to specific areas.

Secondly, the design team and manufacturing team also need to consider the physical changes when the hot water bottle is used to eliminate safety hazards.

Therefore, BS1970:2012 clearly stipulates in Chapter 8.2 that spiral stopper hot water bottles must be accompanied by one of the following safety instructions.

(Original)

Hot water bottles with screw stoppers

Each hot water bottle shall be accompanied by at least the following instructions, depending on the design designated by the manufacturer.

a) Hot water bottles designed for partial filling.

• "When filling this hot water bottle, do not use boiling water and fill to a maximum of two-thirds capacity or less. Do not overfill as this might cause the bottle to burst. Hold the bottle by the neck in an upright position and fill slowly to avoid hot water splashing back. Expel air from the bottle by lowering it carefully onto a flat surface until water appears at the opening.
• Screw the stopper sufficiently tight to ensure that there is no leakage.
• Finger-tight should be adequate. Finally, make sure the funnel is empty.
• If there is a possibility that prolonged contact with the skin could occur, an adequate cover should be used to prevent burns.
• Under no circumstance should the hot water bottle be used as a cushion and be sat on.
• Do not fill using water from the domestic hot water system as this can considerably shorten the life of the hot water bottle.
• Prevent contact with hot surfaces.
• Prevent contact with oil or grease.
• When not in use, drain completely and keep, with the stopper removed, in a cool, dry, dark place. Prevent exposure to sunlight.
• Do not place anything on top of the bottle during storage.
• Check the bottle and stopper for wear and damage prior to use.
• Retain these instructions for future reference."