If you need a hot water bottle in a hurry, there usually isn’t time to take a trip to the drug store to buy one. Instead, you can make your own.
Take an empty large plastic bottle that soft drinks come in (be sure it is cleaned well). This needs to be a stronger water bottle. For example, smaller bottles that had water in it are not suitable as the plastic is too thin.
Fill it with hot (but NOT boiling!) water. For extra safety, place the bottle in a sealed ziploc. Then wrap in a towel and use as a hot water bottle.
This is a quick trick if you need a hot water bottle to treat a strained muscle, tummy ache or PMS symptoms.