Single-pulse activity from XTE J1810−197 during our observations with NIKA2 on 2019 March 25. Only the last 10 min of the observation at 150 GHz are shown for clarity, but the activity is similar for the total 50 min on-source. No single pulses are detected at 260 GHz, which may be an effect of spectral index and instrumental sensitivity. Upper panels: zoom (1.25 s around the peak) into a selection of six pulses, and they share the y-axis scale in Jansky units. Bottom panel: 10 min time series. The time resolution in all panels is ≈42 ms, limited by the sampling frequency set for the KID arrays. Many pulses show structure. Most pulses are unresolved.