*3.2. Oxygenation*

There was no association between body temperature and crSO2/cTOI and SpO2, a weak positive correlation between body temperature and HR in the whole cohort as well as a weak negative correlation between body temperature and prSO2 only in preterm infants. Correlation coefficients and *p*-values of body temperature and crSO2/cTOI, prSO2, pFTOE, HR, and SpO2 are demonstrated in detail in Table 2, Figures 1 and 2. In neonates with hypothermia, we did not find any significant correlation between body temperature and crSO2/cTOI, prSO2, HR, and SpO2, (crSO2/cTOI: - = −0.02, *p* = 0.867; prSO2: - = −0.05, *p* = 0.672; HR: - = −0.177, *p* = 0.127; SpO2: - = 0.199, *p* = 0.069), respectively. In hyperthermic neonates, the body temperature did also not correlate significantly with crSO2/cTOI, prSO2, HR, and SpO2 (crSO2/cTOI: - = 0.111, *p* = 0.642; prSO2: - = 0.232, *p* = 0.658, HR: - = 0.300, *p* = 0.186; SpO2: - = −0.335, *p* = 0.118).

**Figure 1.** (**a**) Scatter plot of cerebral tissue oxygen saturation (%) and body temperature (◦C) in term and preterm neonates. (**b**) Scatter plot of peripheral tissue oxygen saturation (%) and body temperature (◦C) in term and preterm neonates.

**Figure 2.** (**a**) Scatter plot of heart rate in beats per minute (bpm) and body temperature (◦C) in term and preterm neonates. (**b**) Scatter plot of arterial oxygen saturation (SpO2)% and body temperature (◦C) in term and preterm neonates.

**Table 2.** Correlation analyses of body temperature in degrees Celsius (◦C) and cerebral tissue oxygen saturation (crSO2/cTOI), peripheral tissue oxygen saturation (prSO2), peripheral fractional tissue oxygen extraction (pFTOE), heart rate in beats per minute (bpm), and arterial oxygen saturation (SpO2).

