Fig 1. Calorimetric Assessment During an Initial 60% N₂O Administration Distinguishes Initially Sensitive from Initially Insensitive Rats.

Thermal profiles ± pointwise SE (shaded areas) of rats designated as initially sensitive (IS, n = 16) and initially insensitive (II, n = 16) based upon a N₂O screening test of n = 189 candidates. A: Core temperature (Tc); B: heat production (HP); C: dry heat loss (DHL), and D: evaporative heat loss (EHL). HP data between 0 and 12 min are not depicted because it has been documented that the initiation of N₂O delivery can cause a transient artifactual effect on HP [14].