Are there things in Islam that are permissible out of necessity, and others that are not permissible no matter how dire the necessity, and what are examples of each?

The Islamic Sharia came to bring benefits and avert harms. Therefore, forbidden things become permissible out of necessity, in accordance with the rule "Necessities permit the prohibited," while observing that "Necessities are estimated according to their measure." Exceptions to this include killing a human being or eating carrion, and drinking alcohol for thirst. However, it is permissible to drink it under compulsion or to dislodge something stuck in the throat.