QUESTION

Can you please share your thoughts on chemical hand warmers on Shabbat?

ANSWER

The bottom line is that I don’t think it is a problem. The exact parameters of molid are difficult to define, but there is enough evidence that cases like this do not constitute molid. As to generating heat, when it is not bishul and not creating halakhic fire, there is no issur. Many poskim are matir the nightsticks, which you break and then they glow, and that is in my opinion more molid-like than this. People get antsy when heat is involved, but with the nightsticks light is involved, so I honestly don’t see the difference. The case of the nightstick could be argued is sakanah (dark outside, cars don’t see you), but being cold is at least חולה כל הגוף – הכל חולים אצל צינה, and I don’t think people would be using this unless they were really cold.

So, I don’t think there is any issur, but even were one to argue there is an issur derabanan or something similar, these cases are effectively cases of choleh, so it is fine.