Detailed Instructions: Given a passage and a query based on the passage, generate an unambiguous, concise and simple answer to the query from information in the passage. Note that the answer may not be present in exact form.
Q: Product: You recharge this electronic hand warmer via USB. (Expect it to take about 65 minutes to fully power up.) Unlike classic hand warmers designed to nest in the palm of a glove, the GreenHeat looks like a medium-size candy bar that you grip in your hands. Hand warmers are small packets which are held in the hand and produce heat on demand to warm cold hands. They are commonly used in outdoor activities. Other types of warmers are available to provide soothing heat for muscular or joint aches. Depending on the type and the source of heat, hand warmers can last from 30 minutes up to 24 hours. The hand warmer was created by Japanese inventor Niichi Matoba. Matoba received a patent for applying the principle of an oxidation reaction that produces hea Hi all - I carry both the Grabber Hand and Foot Warmers in my pack, as emergency gear. Thankfully, I don't use them too much, so I was wondering if they expire. I noticed at the bottom that they have a Validity Date, which I couldn't read, even with a magnifying glass. I sent an email to Grabber Performance, who makes the Warmers products. They promptly replied, indicating that the expiration date is in 4 years from manufacture and the Validity Date (if you can read it) is the same thing as the Expiration Date. Warmers operate on a chemical reaction with air similar to rusting. The warmer ingredients are iron, water, cellulose, vermiculite, activated carbon and salt. The heating process takes place in this fashion: The iron in the pouch, when exposed to oxygen, oxidizes and therefore produces heat (aka, Air Activated). A pair of air-activated disposable hand warmers, US quarter for scale. Hand warmers are small (mostly disposable) packets which are held in the hand and produce heat on demand to warm cold hands. They are commonly used in outdoor activities. Other types of warmers are available to provide soothing heat for muscular or joint aches. Depending on the type and the source of heat, hand warmers can last from 30 minutes (recrystallisation) up to 24 hours (platinum catalyst). The hand warmer was created by Japanese inventor Niichi Matoba. Types of Hand Warmers. When it comes to hand warmers, there are two types of chemical reactions used to generate heat: supersaturated solution and air-activated. These chemical reactions work to produce an exothermic release of heat, but do so through very different methods. Types of Hand Warmers When it comes to hand warmers, there are two types of chemical reactions used to generate heat: supersaturated solution and air-activated. These chemical reactions work to produce an exothermic release of heat, but do so through very different methods. These types of warmers are best implemented when placed in tight spaces, such as in a glove, shoe or pocket. HotSnapZ Reusable Hand warmers & Heat Pads. 1 Easily Reactivated in Boiling Water The heat reverses the chemistry inside and stores the heat for later use. 2 Fast Instant Heat in a Snap Instant Robust heat reaches internal temperature of 120-130F. Self-regulating. The second type of hand warmers use a chemical reaction called a supersaturated solution. These generally contain metal discs in the middle of them. In order to activate heat, the metal disc must be snapped. Hot Hands warmers work like any other chemical warmer... through an oxidation process (rusting). Different ingredients within the warmer have different purposes. What creates a quality warmer? The quality of those ingredients. Query: how does hot hands hand warmers work
A:
Warmers operate on a chemical reaction with air similar to rusting. The warmer ingredients are iron, water, cellulose, vermiculite, activated carbon and salt. The heating process takes place in this fashion: The iron in the pouch, when exposed to oxygen, oxidizes and therefore produces heat.