I just broke in my savage x this winter. It wasen't too cold, but cold enough the engine had a very hard time getting upto temps. At first, with a rag on the cooling head, I could only get the temps upto 150f max. I then used some tin foil and a sock on the head, then I was able to get the temp upto the wanted 200+ range. I would get a temp gun, and use it.. it's better safe then sorry. You have to get the engine upto 200 atleast during the heat cycle, or you won't accomplish the wanted "heat cycle"