I grew up with a Norwegian family and my dad was a butcher. His smoked salmon was second to none. We built him a large brick smoker with steel doors. He always taught me to use a meat thermometer to test the internal temperature of the fish. We used a small fire with either alder or apple wood on it for smoke. We also used charcoal fires with moist wood chips. I can tell the fish is done by looking for the white excretions which is the oil coming out on top. The curing process "cooks" the fish and makes it edible if done correctly without using a hot fire. That is how Lox is made with either cold smoke or no smoke at all. The fish is really cured and not cooked. I prefer my fish to be on the raw side of cooked so 140 degrees if ok by me. A Little Chief won't get hot enough. I know some friends who put the box the smoker came in over the smoker while it is smoking to keep the heat in.

There is a big difference in properly handled and smoked fish and fish that is haphazardly done.