Crafting heat packs or cold packs

Uncooked rice is the reliable all-rounder. It holds microwave heat well and gives it back slowly, staying warm for 15 to 20 minutes. Wheat, flaxseed, and cherry stones also work, with flaxseed holding heat a touch longer and moulding nicely to a sore neck. Avoid anything with added moisture or oil, since it can go rancid or cook inside the bag.

In short bursts, with a cup of water alongside. Microwave the pack for 30 seconds at a time, checking the temperature between bursts, since rice can overheat and even scorch if you blast it too long. The cup of water in the microwave adds a little steam and reduces the risk of the filling drying out and burning. Never leave it heating unattended.

Yes, just freeze it instead. Pop the rice or flaxseed pack in a freezer bag and into the freezer for a couple of hours, and it becomes a flexible cold pack that moulds to a joint. It will not get as icy as a gel pack, which is actually gentler on skin. For a colder option, a sealed bag of frozen peas wrapped in a cloth is the classic.

A natural fibre, cotton or flannel, never synthetic. Polyester can melt or scorch in the microwave, which is both ruined-pack and fire risk territory. Cotton handles the heat fine. A removable cotton cover over the inner bag means you can wash it, since the rice-filled inner cannot go in the wash.

⚠️ Safety note: Use only natural fabric, never synthetic, as it can melt or catch fire in the microwave. Heat in short bursts and never leave it unattended, since overheated grain packs have caused fires.