Grill the trout, turning carefully, until cooked through and the skin is crisp and the internal temperature is 140°F (60°C), about 6 minutes per side. Rest the lemon halves on the grill at the same time, cut-side down, until the surface lightly burns and caramelizes, about 5 minutes.☞ TESTER TIP: Depending on the size of your fish, your grilling time may need to be adjusted.