Temperature sensitivity of OECs was determined in part by the van't Hoff Equation for the apparent heat of oxygenation for the Hb–O2 reaction (ΔH′ = 2.303 ∗ R ∗ ((ΔlogP50) / (Δ1 / T)) kJmol−1,where R=universal gas constant
(0.008314 kJ K−1 mol−1), and T = measurement temperature in K).