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DIY Microwavable Heat Packs

Making your own DIY microwavable heat packs is an inexpensive way to have a reusable heating pad on hand whenever you need one. You can make them with things you probably already have around the house, including an old cotton sock and uncooked rice.

Homemade heat packs can be used to warm cold hands, soothe sore muscles, provide comforting warmth for cramps, or warm up your bed before you climb in on a chilly night. You can also make smaller versions that are easy to take along when you’re spending time outdoors.

The best part is that you don’t need a sewing machine or any special craft supplies to make a simple rice sock heating pad.

What Can You Use to Fill a Homemade Heat Pack?

There are several inexpensive fillers that work well for homemade heat packs.

Rice

Long-grain white rice is one of the easiest fillers to find and is a popular choice for DIY heat packs. I prefer regular uncooked white rice rather than instant rice.

Rice is inexpensive and easy to work with, although it can eventually develop an odor or break down after being repeatedly heated.

Dried Beans or Lentils

Dried beans and lentils are another inexpensive option. They can be used in much the same way as rice.

Keep in mind that beans may have their own smell when heated, and they can eventually need to be replaced after repeated use.

Whole Dry Corn

Whole dry corn, sometimes sold as feed corn or bird corn, is another option for homemade heat packs.

Make sure you’re using whole dry corn and not popcorn kernels intended for popping. Whole corn can make a long-lasting filler, although availability and price will depend on where you live.

Can You Add a Scent?

If you want a scented heat pack, you can add dried herbs such as lavender or rosemary.

I recommend keeping scented additions simple. If you use essential oils, make sure the oil is completely absorbed into the filler before putting it into the fabric, and use caution because adding flammable materials to something that will be heated in a microwave increases the importance of careful heating.

Personally, I think the natural smell of rice or corn is perfectly fine and is the simplest option.

What Fabric Should You Use?

For a homemade microwavable heat pack, choose a clean, natural-fiber fabric, such as cotton or linen.

Old cotton socks, flannel pajamas, cotton towels, fabric scraps, and worn-out clothing can all be repurposed into heat packs.

Avoid synthetic fabrics unless the material is specifically labeled as appropriate for microwave heating. Some synthetic materials can melt or become excessively hot.

The fabric should also be clean, dry, and free of metal decorations, zippers, snaps, or other materials that should not go into a microwave.

How to Make a DIY Rice Sock Heat Pack

The easiest homemade heat pack requires just a clean cotton sock and your choice of dry filler.

What You Need

• 1 clean cotton sock
• Uncooked long-grain white rice, dried beans, lentils, or whole dry corn
• Cotton string or thread, if needed

Step 1: Fill the Sock

Pour your chosen filler into the sock.

Don’t fill it completely. Leave enough room for the filling to move around inside the sock.

I recommend filling the sock about two-thirds to three-quarters full. This gives you a flexible heat pack that can conform to your neck, shoulders, back, stomach, or other areas.

Step 2: Close the Sock

Tie the open end securely in a knot.

If you don’t have enough sock material to tie a knot, you can sew the opening closed with cotton thread.

For a temporary heat pack, you can also tie the opening with cotton string.

Make sure the filling can’t spill out.

Step 3: Give It a Test

Before heating your new pack, check the sock carefully for loose threads, holes, or weak seams.

You don’t want the filling spilling into your microwave.

How to Make a Sewn Heat Pack

If you sew, you can make a more permanent reusable heat pack from cotton fabric.

Cut two pieces of cotton fabric to the size you want. Place them together with the finished sides facing inward.

Sew around three sides, leaving one side open. Turn the fabric right-side out and fill it about two-thirds to three-quarters full with your chosen dry filler.

Don’t overfill it. The filling needs room to move so the finished heat pack remains flexible.

Sew the remaining opening closed securely.

You can make several different sizes this way. A long, narrow heat pack works especially well around your neck and shoulders, while a smaller one is convenient for hands or individual sore spots.

How to Heat a Homemade Heat Pack

This is the part where you want to be careful.

There isn’t one microwave time that works for every homemade heat pack. Microwave wattage, the size of the pack, the type and amount of filler, and the moisture content can all affect how quickly it heats.

When heating a new heat pack, start with a short heating interval and check it before adding more time. VCU Health recommends heating a rice sock cautiously and testing the temperature before using it.

Place the heat pack flat in the microwave and heat it for a short interval. Carefully check the temperature and continue in short increments if additional warmth is needed.

Never leave a homemade heat pack unattended while it is being heated.

Use an oven mitt or other appropriate protection when removing a hot pack from the microwave.

Before putting it against your skin, test the heat pack against the inside of your arm. It should feel comfortably warm rather than painfully hot.

If it is too hot, allow it to cool before using it.

Important Heat Pack Safety

Homemade heat packs are simple to make, but they should still be used carefully.

• Never overheat a homemade heat pack.
• Always supervise it while it is in the microwave.
• Start with short heating intervals rather than assuming a specific time will work.
• Test the temperature before placing it against your skin.
• Don’t place an extremely hot pack directly against bare skin.
• Don’t use a damaged sock or heat pack with holes or loose seams.
• Keep the heat pack dry unless it was specifically designed for moist heat.
• Don’t use synthetic fabrics unless they are specifically appropriate for microwave heating.
• Never put metal, metallic decorations, or metal closures in the microwave.
• Don’t use a heat pack while sleeping.
• Stop using it if it becomes uncomfortably hot.

Heat can cause burns, and medical guidance specifically warns against falling asleep while using a heat source.

If your microwave catches fire, keep the door closed, turn the microwave off, and don’t open the door until the fire is out.

Can You Use a Rice Sock as a Cold Pack?

Yes! You can also use a homemade rice or grain pack as a cold pack.

Place the sealed heat pack inside a clean freezer bag to help protect it from moisture and odors, then place it in the freezer until it is cold.

When you’re ready to use it, remove the homemade pack from the freezer bag and wrap it in a thin towel if needed before placing it against your skin.

A homemade cold pack can be especially convenient because you can keep one in the freezer and have it ready whenever you need it.

How Long Does a Homemade Heat Pack Stay Warm?

That depends on the size of the pack, the filler you use, and how well your particular microwave heats it.

A larger pack will generally provide warmth for longer than a small hand warmer. Rice, beans, lentils, and corn can all work, but each will behave somewhat differently.

Rather than trying to achieve a specific number of minutes, heat the pack until it reaches a comfortable temperature and reheat it in short increments when necessary.

How Long Do Homemade Rice Heat Packs Last?

There isn’t a set expiration date for a homemade heat pack.

With regular use, inspect it periodically for holes, loose stitching, unusual odors, moisture, or changes in the filler.

If the filling develops a strange or unpleasant odor, becomes damp, or the fabric or seams become damaged, it’s time to make a new one.

One of the reasons I like making these from old socks and fabric scraps is that replacing one doesn’t cost much.

Why Make Your Own Heat Pack?

A store-bought heating pad can certainly be convenient, but a homemade heat pack has a few advantages.

It’s cheap, reusable, customizable, and easy to make. You can make one from an old sock in just a few minutes, and you can choose the size and filler based on how you plan to use it.

They’re also a great way to repurpose clean socks, clothing, and fabric that might otherwise end up in the trash.

If you make several different sizes, you can have a small one for your hands, a longer one for your neck and shoulders, and a larger one for your back or legs.

If you’ve never made a homemade heat pack before, a simple rice sock is the easiest place to start. All you need is a clean cotton sock and some uncooked rice.

It’s one of those simple DIY projects that costs very little but can be surprisingly useful around the house. Just remember that homemade heat packs can become very hot, so always heat them cautiously, check the temperature before use, and never leave them unattended in the microwave.

Once you’ve made one, you may find yourself making several to keep in different rooms of the house!