Temperature Oscillation (ΔT) as an Ecological Marker of Autonomic Coherence

Axillary temperature oscillation (Delta T; night-minus-morning) serves as an accessible ecological proxy for autonomic coherence and energetic resistance to stress (eR), reflecting regulation by the suprachiasmatic nucleus and core clock genes (PER, CRY, CLOCK, BMAL1). The Energy Resistance Principle (ERP) posits that elevated eR promotes oxidative stress, inflammation, and accelerated aging. The MiSBIE index (Mindful Self-Biofeedback Index of Embodiment) is a validated six-domain cognitive-autonomic metric (mental clarity, energetic vitality, emotional balance, tension release, bodily interoception, and subjective rhythmic synchrony; r = 0.78 vs EEG/HRV; Cronbach alpha = 0.89).

This 15-day prospective ecological study in free-living routine evaluated Delta T, MiSBIE variation, morning light exposure, and nighttime screen use as real-world proxies of eR in 16 adults (9 F, 7 M; mean age 58.35 +/− 7.8 years), achieving 100 percent adherence (239 of 240 records). Delta T greater than 0 C identified elevated eR (r = 0.52 with perceived stress; 95 percent CI 0.38 to 0.64; p < 0.001). K-means clustering (k = 3) revealed three phenotypic patterns: Profile A (low eR and high coherence; n = 5): Delta T −0.17 +/− 0.21 C, MiSBIE change +4.82 +/− 1.98 (p = 0.0078); Profile B (high eR and incoherence; n = 6): Delta T +0.35 +/− 0.48 C (p < 0.001 vs A), MiSBIE change −2.11 +/− 3.42 (p = 0.0416); Profile C (compensated eR and hormesis; n = 5): Delta T +0.28 +/− 0.32 C, MiSBIE change +1.23 +/− 2.61 (p = 0.31). MiSBIE predicted 78 percent of eR variance (R2 = 0.78; p < 0.001). Morning light exposure greater than 15 minutes reduced eR (beta = −0.24 C; 95 percent CI −0.39 to −0.09; p = 0.002), while nighttime screen exposure correlated with lower MiSBIE (r = −0.32; p = 0.012).

Limitations include axillary temperature bias (about −0.1 C vs core), self-reported behavioral variables, and the absence of continuous HRV or serum GDF15. Delta T combined with MiSBIE enables low-cost, real-world detection of eR phenotypes and supports algorithmic frameworks such as Verso 1.0 for early, light-based physiologic interventions aimed at restoring autonomic coherence and reducing aging-related risk.

Author summary

As an independent researcher, I investigated whether simple axillary temperature measurements taken at home could reveal how a person’s stress and energy systems are functioning in daily life. Core ideas behind this work come from the Energy Resistance Principle (eR), which proposes that the body’s resistance to stress influences inflammation, mood, and aging. To explore this in the real world, 16 adults tracked their temperature twice a day for 15 days, along with morning light exposure, screen use at night, and a brief self-assessment called MiSBIE, which reflects how mentally and physically balanced a person feels.

By analyzing these daily patterns, we identified three different profiles: one with good balance and low stress load, one with higher stress and disrupted rhythms, and one that showed signs of adaptation. People who received more morning light tended to show healthier patterns, while nighttime screen use was linked to worse self-regulation.

These findings suggest that simple tools—temperature, light exposure, and self-reflection—could help create low-cost digital solutions for early detection of stress-related problems, especially in communities with limited access to healthcare.