Best heat pack filling?

[JackieLikesVariety]

hello @thylacine, how did I miss this thread?

I have a lot of trouble with cold hands and feet, the older I get the more I understand why moving south as you age is a thing.

decades ago I used battery powered socks I got for horseback riding in winter, low tech but worked.

(I'm interested in those disposable ones you see in sporting goods that you activate and put in your gloves. how do those work, anyway?)

also have used a home-made hotpack that was filled with rice. you put it in the microwave and then drape it around your neck.

anyway, I'm interested in the subject.

the rice worked, I can tell you that