In order to get a successful heart or lung shot, it is highly recommended to use a weapon equipped with an infrared sight. These shots are possible without the infrared, but will be difficult. Once you have infrared equipped on your gun, start the hunt you are trying to complete. Target and zoom in on the chest of your target. The infrared button will be in the bottom left hand corner of your screen, next to your targeting function. Tap the infrared and the screen will now show the heat signatures from the Dinosaur. You will see two ovals (lungs) and a small round ball (the heart) in between the ovals. Take aim and take your shot, but do it quickly, as infrared does not last long.  Extra batteries to recharge the infrared may be purchased.