Poke meat with a temperature fork? Don't you dare. "I don't believe in forks for grilling. It's too tempting to want to stab the meat, and poking holes in the meat lets out the juices," says Steven Raichlen, author of Planet Barbecue. "When I need to take a meat's temperature, I use a good instant-read thermometer, like the Thermapen by ThermoWorks."
Reinhardt sums it up simply: "Why poke your meat twice when you can poke it only once?" We can't argue with that logic.