I am having trouble getting whitebait to the correct internal temperature. After I simmer it for a few miniutes I put the thermometer in and it goes up to 42c and not 63c(145f) which is the safe temp for fish. Im not sure whether because the fish is small its not possible for the reader to get a correct reading. the points on my thermometer are quite big and probably for larger cuts of food though it seems to go in the flesh.
the problem is if i cook it to a higher temp it just overcooks. so am i cooking it safely and correctly or not? is my thermometer reliable, what am i doing wrong since safe seems to be overcooked and cooked seems to be unsafe, it could also have to do with my thermometer but not sure.