Fig. 4: Association between core temperature and secondary cardiac outcomes in the climate chamber and perfusion suit studies.
Figure shows the model-predicted relations of the change in cardiac output (top; 79 studies, 114 effect estimates), systolic blood pressure (middle; 212 studies, 337 effect estimates), and rate pressure product (bottom; 205 studies, 303 effect estimates) as a function of the change in core temperature from baseline to end-heating in studies employing a climate chamber (gray) or perfusion suit (red) to induce heat stress. Model predictions (left) are presented as means (lines) and robust 95% confidence intervals. Analyses were also adjusted for the method used to measure core temperature. Model estimates and P-values (reported in the main text) were not adjusted for multiple comparisons. Data for hot water immersion and sauna studies are shown in supplemental Figures S33-S35 (pp 89–90), respectively. Model diagnostics are provided in supplemental Figures S35-S46 (pp 92−103). Model estimates and P-values (reported in the main text) were not adjusted for multiple comparisons. Individual effect estimates (right) are sized according to their weight in the meta-analytic model. The marginal distribution of individual effect estimates (unweighted) for each outcome modality is depicted on the right side of the panel. The effect estimate for the seminal study by Rowell et al.18 is also highlighted, which was among the first to assess the physiological limits of cardiac responses to heat exposure and is also commonly cited in translational reviews describing heat’s effects on the heart.
