Meat thermometers have probes with the sensor in the tip of the probe. They are designed to be inserted into the thickest part of the meat and give you a real temperature reading. Bone will be hotter due to the nature of bone, so if you insert a probe and it touches the bone it is going to give you a false reading and the meat may not reach the correct safe internal temperature needed to kill any bacteria that may be present in the food. If you insert the probe and it hits the bone, reposition the probe into the thickest part of the meat. Remember, you need to take temperature readings in several separate locations to determine if the food has reached the correct temperature.