A hand warmer is a small disposable packet that produces heat on its own to warm the hands when they get cold. It is an air-driven, convenient, efficient, and portable source of heat that requires no external force to operate. When it’s cold, it works like magic to keep your cold hands warm, but does it continue to keep your hands warm after it expires?
In most cases, hand warmers still function after expiration if they are stored correctly. However, there will be a slight difference in its functionality, such as longer heating time or may not heat like an unexpired hand warmer. Even though hand warmers continue to function after they expire, it is always advisable to bring along an additional, hot hand warmer that hasn’t expired for every one that has.
How Do Hand Warmers Work?
A hand warmer contains a disposable pouch packet in an airtight packet. There are different types of hand warmers that function differently but mostly it contains salt, activated carbon, water, iron and an absorbed material.
As soon as the pouch is removed from its outer packaging the oxygen reacts with the iron powder inside in the presence of salt and water (oxidation) to produce iron oxide (Fe2O3) which in result generates heat. Meanwhile activated carbon aids in the equal distribution of heat, while absorbent materials like vermiculite aid in the retention of water content.
Because the entire reaction depends on exposure to air, it functions properly in an environment that is well-aerated. The main mechanism of hand warmers is the rusting of iron which produces heat.
What is the Shelf Life of Hand Warmers?
The shelf life of hand warmers varies on its storage but it typically remains intact for three to four years when unopened. Once the packet is opened, it will remain usable until the iron powder has completely oxidised, at which point it will be thrown out. Protecting the hand warmers from direct air contact is essential to extending its shelf life because oxygen will initiate the oxidation reaction.
Some hand warmer packaging may fail to prevent air contact, so it is best to store your hand warmers in an airtight container or bag if you intend to use them for an extended period of time.
We Recommend the Following Warmers
1. HotHands Hand Warmers
Designed and made in the US, hothands hand warmers are single use hand warmers that can help you keep your hand warm during cold. It consists of 80 hand warmers or 40 pairs. Hothands hand warmers provide a safe and natural heat to keep your hand warm even in tough conditions. It is odourless, easily disposable and has a long lasting effect. Hothands hand warmer usually takes 15-30 minutes to heat up.
Hothands hand Warmers has an expiry date of 3-4 years. You can open it anytime during this period. Hothands hand warmers don’t demand shaking or kneading before using them. These hand warmers are designed in such a way that it is easily portable and can fit in your hands and pockets.
2. Sport Temp Large Hand and Body Warmers
Sport temp hand warmers consist of 45 individual hand warmers. It can be easily stored anywhere. Activating sport temp hand warmers require 15-30 minutes. To activate the hand warmer, open the package, remove the warmer and just shake. Sport temp hand warmers offer 18 hours of lasting heat. Whether you’re going to use it for fishing, skiing or snowboarding, it is the best option. Sport temp hand warmers have a shelf life of 3 years. These hand warmers are odourless and can be stored in pockets, jackets or bags. As the ingredients of this hand warmers are harmless, it can be easily disposed of.
3. Hot Hands Hand Warmers - 11 Hours Lasting
Hothands is one of the leading brands in the world when it comes to air activated hand warmers. They are trusted by a lot of people including athletes, hikers, outdoor workers, skiers, etc.
Activating this hand warmer takes only a little time and it can last up to 11 hours. Heating and reheating is easy with this hand warmer. All you need to do is expose it to air and just shake it. You can use it on your gloves or hands to start feeling the warm during cold. This hand warmer from hothand is ultra thin and is easy to store. It comes with a total of 40 packs of hand warmers. Like the other hand warmers from hothands, this one is also safe, odourless and made from harmless products.
The natural rusting process is used by hand warmers to generate heat on the go. In the presence of moisture and salts, it initiates the oxidation reaction with the aid of iron and oxygen to generate heat. Its functionality may suffer slightly after its expiration, but it still works in some cases. The lifespan of hand warmers varies depending on how they are stored.