Two infrared imagers, both with a 3- to 5-um spectral range, were tested in a smoke-filled opening to determine their capability to "see through smoke." A mine opening 75 meters long was filled with coal smoke. A fire in a smoke generator and two men were used as targets. The men were detected and identified at 75 meters. Tests were discontinued on the fire because the instruments were saturated with the fire at 25 meters, indicating that fire could be detected at much greater distances. Because of their ability to "see through smoke," infrared imagers should be useful during rescue operations in smoke-filled mines.