According to its filling materials, hot packs can be divided into the following three types:

1. Hot water bottle

This type of hot pack usually uses rubber as raw material, and the user fills it with hot water during use. Because of its low price, this type of hot pack is the most common heat source. Recently, there are also many cute hot water bottles on the market, which are very popular.

It is a pity that burns caused by overturning or leakage during hot water filling are also very common, so it is not recommended for older or young children to use it alone without the company of a healthy adult.

2. Gel hot pack

The content of such hot packs is usually Propylene glycol. Because it has no contact toxicity and does not harden at low temperatures, it is also used for cold therapy.

Risks include burns caused by leakage. In the past, there have been reports of users blasting the hot pack during heating. For this reason, even if they claim that they can be heated in a microwave oven, they must be very careful. In addition, the gel used in some of these products is a toxic substance, glycol. Taiwan and Australia used to have large-scale recycling.

3. Herbal filling

This type of hot pack is a high-end product. Due to its high price, it is not often sold in retail stores in the market.

The filling material is usually plant seeds or vanilla. The principle is that there are so many tiny holes on the surface of such plant materials, and the indoor environment will slightly regain moisture. Therefore, when heated by a microwave oven and the moisture is heated by the microwave, the effect of moist fumigation can be achieved. Some products will also use vanilla to give a light fragrance when used. Some products use traditional Chinese medicine, but the effect of hot moxibustion has not been determined.

If the product is placed in the refrigerator, it can also be used for cold therapy, namely ice pack.