Hebrew | Francais


> > Archive

Shabbat Parashat Vayishlach 5780

Ask the Rabbi: Heating Pad on Shabbat

Rav Daniel Mann

Question: I have muscle pain in my back, which sometimes becomes severe. Going to bed with a heating pad has made a big difference sometimes. May I use it on Shabbat, or is it a problem of muktzeh?


Answer: There are a few issues of muktzeh involved here. One is whether to consider a heating pad a kli shemelachto l’issur or a kli shemelachto l’heter. On the one hand, in order to use it, one must put it on, which it is forbidden on Shabbat. On the other hand, if one prepared it before Shabbat (by keeping it on or setting a Shabbat clock), then further use does not include melacha. (We are not delving into issues of medical activity on Shabbat. While not a trivial question, with the level of need involved, there are ample grounds to permit it – see The Halachos of Refuah on Shabbos, p. 26.). Rav Moshe Feinstein (Igrot Moshe, Orach Chayim III:49, regarding an electric fan) treats such items as kli shemelachto l’issur. However, regarding a case very similar to ours, an electric blanket, he raises the serious possibility that it is a kli shemelachto l’heter. This is also the opinion of Rav S.Z. Auerbach (Minchat Shlomo I:9) and Rav Asher Weiss (Shut Minchat Asher I:33), although none of them was willing to rely on this heter alone. In any case, it is permitted to use a kli shemelachto l’issur for a permitted use (l’tzorech gufo) (Shulchan Aruch, OC 308:3) and this would be a classic example.

A further problem is the fact that the heating pad has a filament that becomes glowing hot. In certain areas of halacha, this is considered like fire (see Shemirat Shabbat K’hilchata 43:4 regarding using an incandescent light for hadlakat neirot Shabbat in a case of need). We find that a lit ner (oil cup) is full muktzeh, which cannot even be moved for a permitted use (Shabbat 47a). This is because the flame is muktzeh (more than a kli shemelachto l’issur), and the oil and cup are a bassis l’davar ha’asur (something which is supporting that which is muktzeh). So ostensibly, the whole pad is a bassis for the heat-emitting electrical wires, which are the heart of the device (Orchot Shabbat 19:(246)).

We must understand why the gemara posits that a flame is muktzeh. One answer in the Chazon Ish (OC 41:16) is that the fact that one does not move a flame on Shabbat (since it can go out) makes it muktzeh. Another answer he suggests is that the flame is considered nolad, something that did not exist before, as the flame is constantly renewing. Rav Asher Weiss (in a letter to Zomet) says that it is because a flame is a separate unit that does not fit into one of the categories that would make it not muktzeh (i.e., food, a utensil).

Even according to the Chazon Ish’s explanations, the heat-producing electricity might not be like a flame (see Minchat Shlomo I:14, who analyzes this Chazon Ish). In any case, several contemporary poskim posit (including Igrot Moshe, OC III:50), mainly in the context of an electric blanket, that we do not view the heated wires and the electricity therein as a separate unit like a flame is. Rather, it is subsumed under the overall utensil of the blanket, which is either a kli shemelachto l’heter or kli shemelachto l’issur (see above), but, either way, it can be moved as part of its use. Rav Ovadia Yosef (Yechaveh Da’at V:28; see also Chelkat Yaakov, OC 118) adds also that the electricity in the wires are not comparable to a flame because the results are not visible. However, many, including Rav S.Z. Auerbach (Minchat Shlomo I:14), permit to move even lamps whose electricity gives off a noticeable light. In the final analysis, then, it is permitted to use the heating pad.

Rav Moshe Feinstein (Igrot Moshe ibid.) required attaching a reminder to the controls and the wall socket so that one not change the setting or unplug it. Rav Ovadia (Yechaveh Da’at ibid.) considers that a new gezeira and therefore unnecessary, although he also wrote that it does not hurt to be stringent. All agree that one does not have to be concerned lest he inadvertently pull it out of the wall, against his intention.

Top of page
Print this page
Send to friend


We daven for a complete and speedy refuah for:


Nir Rephael ben Rachel Bracha

Refael Yitchak ben Chana

Netanel Ilan ben Sheina Tzipora

Netanel ben Sarah Zehava

Meira bat Esther

Yair Menachem ben Yehudit Chana

Rivka Reena bat Gruna Natna

Lillian bat Fortune

Yafa bat Rachel Yente

Eliezer Yosef ben Chana Liba

Ro'i Moshe Elchanan ben Gina Devra

Esther Michal bat Gitel

Yehudit Sara bat Rachel

  Together with all cholei Yisrael


Hemdat Yamim is dedicated

to the memory of:

those who fell in wars

for our homeland


Eretz Hemdah's beloved friends

and Members of

Eretz Hemdah's Amutah


Rav Shlomo Merzel z”l
Iyar    10


Rav Reuven Aberman z"l

Tishrei 9  5776


Mr. Shmuel Shemesh  z"l
Sivan 17 5774


R' Eliyahu Carmel z"l

Rav Carmel's father

Iyar 8  5776


Mrs. Sara Wengrowsky

bat R’ Moshe Zev a”h.

Tamuz 10    5774


Rav Asher Wasserteil z"l

Kislev 9 5769


R'  Meir ben

Yechezkel Shraga Brachfeld z"l


R'  Yaakov ben Abraham & Aisha


Chana bat Yaish & Simcha

Sebbag, z"l


Rav Yisrael Rozen z"l
Cheshvan 13, 5778


Rav Benzion Grossman z"l
Tamuz 23 5777


Rav Moshe Zvi (Milton)

Polin z"l

Tammuz 19 5778,


R' Abraham Klein z"l

Iyar 18


R' Yona Avraham

ben Shmuel Storfer z”l

19 Kislev


Hemdat Yamim
is endowed by Les & Ethel Sutker
of Chicago, Illinois
in loving memory of
Max and Mary Sutker
Louis and Lillian Klein, z”l



site by entry.
Eretz Hemdah - Institute for Advanced Jewish Studies, Jerusalem All Rights Reserved | Privacy Policy. | Terms of Use.