Neuroleptic malignant syndrome
Neuroleptic malignant syndrome (NMS) is a rare but life-threatening reaction that can occur in response to ingesting antipsychotics (neuroleptics) or other drugs that block the effects of dopamine. Symptoms include high fever, confusion, rigid muscles, variable blood-pressure, sweating, and fast heart-rate.
Source: Wikipedia — Neuroleptic malignant syndrome (CC BY-SA 4.0)