Effect of Elevated Temperatures on Inflammatory Cytokine Release: An In Vitro and Population-Based Study

Extreme high temperatures in the summer have become a global concern, and their risks to the inflammatory system have been largely unknown. Here we appraised the exposure risks of summer heatwaves by comparing the sera cytokine levels in healthy individuals under high and normal temperatures. In addition, we established a cell model with a 1.5 °C temperature increase to investigate the regulatory mechanisms of temperature-related cytokines. Our results suggest that elevated temperatures enhance the release of interleukin-6 (IL-6) and interleukin-8 (IL-8) via the aryl hydrocarbon receptor (AhR) pathway and augment the pro-inflammatory effects of other factors. This suggests that we may have underestimated the impact of high temperatures on the health of individuals beyond just mortality rates. Moreover, seemingly minor temperature increases of just 1.5 °C can still pose a challenge to cells.