Detection of T-wave inversion is dependent on the ECG lead. (A) In python 1, in the course of heating from 25.1°C (blue) to 35.2°C (red), the T-wave inverted in lead aVF (bottom traces) but not in lead I (top traces). (B) A vector cardiogram of the T-wave before and after heating. (C) A graph showing the T-wave vector based on lead aVF and lead I before (blue dot) and after heating (red dot) for pythons 1-5.