Extreme hyperthermia-induced arrhythmogenesis.

Hyperthermia is defined as an elevated body temperature above the normal range due to a failure of heat regulatory mechanisms. In addition to its effects on other organ systems, hyperthermia is associated with profound cardiovascular effects. We report the sentinel case of a 6-year-old girl with structurally and electrically normal heart, who presented with life-threatening hyperpyrexia-induced ventricular tachycardia, which was refractory to cardioversion and anti-arrhythmics but responded promptly to cooling. We emphasise the lifesaving role of immediate and aggressive cooling in such patients.