How to Make a Chemical Heat Pad

A chemical heat pad can easily be made at home with a process known as supersaturation. In this example, a solid substance, sodium acetate, is heated and dissolved in a liquid. In a supersaturated state, the substance is unstable and can crystallize with the slightest amount of pressure. With sodium acetate, the crystals give off immediate heat that can last well over 30 minutes.

Things You'll Need

• Sodium acetate
• Water
• Saucepan
• Wooden spoon
• Small sealable plastic bag
• Large sealable plastic bag

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Instructions

• 1

  Pour ¼ cup of sodium acetate into a clean saucepan. Add just enough water to cover the sodium acetate crystals.

• 2

  Put the saucepan on the stove at medium heat. Stir the mixture with a wooden spoon while the sodium acetate crystals absorb and excess water evaporates. Take the saucepan off the heat once the sodium acetate has a gel-like consistency.

• 3

  Pour the sodium acetate into a small sealable plastic bag and seal it. Leave any undissolved sodium acetate crystals in the pan.

• 4

  Put the bag into a larger sealable plastic bag. Seal the larger bag and put it in the refrigerator in a spot where no other objects can fall or bump into it. Let the sodium acetate mixture chill for at least 15 minutes.

• 5

  Remove the bag from the refrigerator once you're ready to use it. Squeeze the sodium acetate gel to cause a chemical reaction. The substance will rapidly heat up and form a consistency similar to ice.