Table 1.

Best-fit model results of CT_max and CT_min as a function of latitude and elevation

Fixed effect	coefficient	SE	t-value	p-value
CTmax
intercept	39.26	3.08	12.75	<0.0001
absolute latitude	0.318	0.077	4.13	0.0001
elevation (km)	−1.02	0.45	−2.26	0.0253
absolute latitude2	−0.0069	0.0014	−5.02	<0.0001
latitude:elevation	−0.01	0.02	−0.90	0.369
CTmin
intercept	14.04	1.70	8.24	<0.0001
absolute latitude	−0.41	0.04	−11.0	<0.0001
elevation (km)	−4.22	0.58	−4.56	<0.0001
latitude:elevation	0.052	0.020	2.55	0.0124
cold limit metric (lethal)	−2.78	1.02	−2.72	0.0076

A quadratic term for absolute latitude is included in the CT_max model based on Akaike Information Criterion (AIC) results (Table S2). For CT_min, a cold-tolerance limit metric is included to account for possible differences between critical thermal limits (base level) and lethal thermal limits (contrast shown). Model results are for thermal limits corrected for acclimation temperature; see Table S3 for model results on uncorrected data.