Supplementary Fig. 1 Distribution of (a) measured and standardized Tcrit and (b) warming tolerance (warming tolerance = Tcrit - Tmax where Tmax corresponds to the mean temperature of the warmest month). Note that the standardization procedure tends to decrease not only mean Tcrit and warming tolerance but also their variance. Importantly, extreme values decrease to a substantially degree, ultimately increasing the signal-to-noise ratio of subsequent analyses. Tcrit was standardized for a 24 h exposure after accounting for mass effects.