Is it permitted to submerge a vessel with cold liquid inside a vessel of hot water on Shabbat to warm it (a practice common in winter)?
Synopsis
The Taz prohibits the common winter practice of inserting a vessel with cold liquid into a container of hot water on Shabbat, ruling it is full hatmanah. The Aruch HaShulchan records this as a real-world concern and adds a related case involving a kugel vessel in a cholent pot in a hot oven.
More in Insulating with Heat-Generating Materials
Is it permitted on Erev Shabbat (while still daytime) to place a vessel containing cold food on top of a warm pot?
5 opinions across 3 eras
If the warm lower pot is still sitting on an open fire, does placing a cold vessel on top of it on Erev Shabbat remain permitted?
3 opinions
Is it permitted on Shabbat itself to place a cold vessel on top of a warm pot (not on fire) to warm it, particularly when the pot is covered with cloth?
3 opinions
Is it permitted to cover a vessel of hot tea or similar drink with a cloth (mafteches/towel) on Shabbat to keep it warm?
2 opinions
What is the reason the warm pot is not considered a 'heat-adding insulator' (davar hamosif hevel), and does this reasoning have any limits?
3 opinions
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Discussion
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