My ipad was destroyed with a hammer and very hot. Will it cool down on its own

It's entirely possible the battery has been damaged, such that it may burst into flames. And these types of batteries burn intensely hot!

Keep it far away from anything flammable. Or take it to a hazardous waste disposal site, making sure let them known the battery may combust.

But, you also may need to keep it for evidence of a criminal act. In which case, put it somewhere like the middle of a garage floor on the cement, with nothing else around it for at least six feet.

Put it outside on concrete or slabs and and far away from anything that can burn.

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