It’s forbidden to insulate on Shabbos itself even if the material does not add additional heat. (Lest one come to heat up the food to peak temp before insulating)

If one insulated correctly before Shabbos and it subsequently fell off, it is ok to replace the insulation

Cold water may be insulated. (Rashi explains it means to keep it cool)

Cold food that is typically insulated to keep hot- there’s a dispute whether it’s ok to insulate it to keep it cold. Rebbe himself switched his opinion on the matter

There is no prohibition of בישול עכום with water.

One can add additional layers of insulation to food on Shabbos. Moreover, one can switch the insulation on Shabbos

It is permitted to insulate a כלי שני.

If a pot lid is muktzeh and completely closes the pot, there is no way to get out the food.

One cannot crush snow or hail on Shabbos. (Rashi says it’s like creating new water.) but it’s ok to put ice inside a cup of water

Ones animal can’t do work on Shabbos, like carrying. However, a rope used to lead a camel is not carrying. (Anything for the animals well being is not a “burden.”)

A female dromedary needs more retaraisnt and she can go out with a nose ring leash. For her, a rope would be carrying, bc it’s ineffective. The nose ring for a camel is excessive restraint and that’s a matter of doubt in the gemara if it’s ok. Ultimately the gemara favors the opinion that permits that.

Any animals that usually go out with a collar may go out with collars and be pulled by them.

A rope collar for big beasts is carrying bc it’s ineffective. For a small beast it’s ok. For a cat it is excessive restraint and it’s a matter of dispute, but again, like the camel with the nose ring, the gemara favors they opinion that permits it.