Spectral type and stellar effective temperature versus total flare temperature for different photometric and spectroscopic studies: The upper panel uses the stellar effective temperature if available from the TESS input catalogue (Stassun et al. 2019). For the Kowalski sample, we use conservative uncertainties of ±500 K. The lower panel shows a density map of flare temperatures per spectral type that is consistent with the upper stellar effective temperatures. The flare temperature axis is represented in log-scale. The two TRAPPIST-1 flares are overplotted and the blue horizontal lines represent the average temperatures from the two biggest temperature samples.