Even the most experienced and recognized chef uses a BBQ thermometer. No matter how tempted you are to check food temperatures manually, avoid it. Always trust the thermometer to produce accurate readings for your meat as it cooks. Even if you have a thermometer, also use a food temperature chart.
It will tell you the correct temperatures to use when cooking poultry, pork, beef, lamb, veal, ground meat, and so on. If you cook all kinds of meat, get familiar with safe cooking temps for all of them. Here is the list we are talking about: