Hot yoga is yoga in a heated and humid room, if it's specifically Bikram yoga it's done at 108 degrees and 40% humidity, a sequence of 26 poses three times in a row. Cobra is a backbend where you are laying down prone and you lift your chest and head up using your back muscles (to the belly button), it's the easier version of upward facing dog, which is the same body position except you are lifted up and only your hands and the tops of your feet touch the ground.