Most oral thermometer’s tips are elongated, but they can be pear or stubby shaped. The elongated tip allows more contact with the surface, giving a quicker and more accurate reading. An anal thermometer’s tip is blunted, round and thick. The rounded tip is safer (not as apt to break or puncture the walls of the rectum) and more comfortable. Most anal thermometers have a red tip or mark, to remind you that they are anal thermometers. Most oral thermometers have a blue tip or mark.