Antonyms for the term "Malignant Hyperpyrexias" could include words such as benign, non-threatening, or non-malignant. These antonyms describe conditions that are not dangerous or life-threatening, unlike Malignant Hyperpyrexias, which is a medical emergency that can result in death if not treated promptly. Other antonyms could include words like mild, minor, or inconsequential, which hint at the lack of severity associated with the conditions they describe. In contrast, Malignant Hyperpyrexias is characterized by uncontrollable muscle contractions, fever, and other potentially life-threatening symptoms, making it a serious condition that requires immediate medical attention.