With its dense population and high industrial and agricultural activities, South Asia ranks among the most polluted regions in the world. In early November 2023, a severe air pollution event was recorder in the region along the Himalayas, the Indo-Gangetic Plain (IGP), degrading air quality over hundreds of kilometers. This episode coincided with and was caused by the burning of agricultural waste by local farmers, releasing large amounts of pollutants, including carbon monoxide (CO), into the troposphere. Additionally, the stable meteorological conditions of the post-monsoon season (October to November) favored air mass stagnation, facilitating the build-up of CO, from anthropogenic and biomass burning sources, in the region. In this study, we investigate these anomalous CO concentrations as detected from space by the IASI and TROPOMI instruments, on board the polar-orbiting Metop-B and -C and Sentinel-5P satellites, respectively. We observed discrepancies in CO detection between the two instruments, attributable in part to their sensitivity in probing gases near the Earth's surface. Although satellite thermal infrared sounders are considered to have limited sensitivity near the surface, we demonstrate here that IASI can detect CO close to the surface, under high thermal contrast conditions (difference between the surface temperature and the atmospheric layer just above the surface). In fact, nighttime CO was generally discarded because of the lower sensitivity of IASI at night. This extreme pollution event exemplify a particular scenario of high thermal contrast scenes in particular at night favoring IASI-CO detection and illustrating the added value of nighttime thermal infrared measurements.