[en] Electron temperature fluctuations are correlated with the dominant (m, n) = (0, 1) edge-resonant magnetic tearing mode during sawtooth events in the Madison Symmetric Torus reversed-field pinch. Electron temperature fluctuations in phase with the (0, 1) tearing mode are measured using high-repetition-rate Thomson scattering. Immediately prior to the sawtooth the (0, 1) island structure appears to be heat-confining, while during the sawtooth it assumes an isothermal character. Core electron temperature variation is also phase correlated with the (0, 1) mode, suggesting that the edge-resonant tearing mode has an effect on core electron thermal confinement during sawtooth events. (brief communication)