Irreversible MAOIs: agitation, delirium, coma, hyperpyrexia (high fever), seizures and severe changes in blood pressure.
In the Franco-German War the cooling bath was largely employed, in conjunction frequently with quinine; and it was used in the treatment of hyperpyrexia.
Other signs of overdose may include: confusion, disturbed concentration, transient visual hallucinations, dilated pupils, agitation, hyperactive reflexes, stupor, drowsiness, muscle rigidity, vomiting, hypothermia, hyperpyrexia.
This condition is known by a number of names, including malignant hyperthermia (MH), malignant hyperthermia syndrome (MHS), and malignant hyperpyrexia.
Prof. Whyte records that Michael Denborough's research unit on malignant hyperpyrexia remained on the 5th floor of the main block of RCH "until its dying days."
Meperidine HCl (Demerol), an opioid, has been associated with hypertension, hyperpyrexia, skeletal muscle rigidity, seizures, and coma when used with MAOIs.
Also, if the atmosphere is as warm as or warmer than the skin during times of high humidity, blood brought to the body surface cannot dissipate heat by conduction to the air, and a condition called hyperpyrexia results.