There are a few possibilities about the low oil temperature:
1. The story is true as reported (175°F seems a little low)
2. Someone can't convert from Fahrenheit to Celsius (175°C = 350°F)
3. Someone got the temperature completely wrong
Why the guy chose an oil bath (which might have been cooling off from the previous day's work) instead of a furnace is beyond me, unless he couldn't get access to the inside of a furnace.
We have furnaces (we make forgings, and we do a lot of heat-treating in-house) that go up to 2200°F+. At that temperature, I figure a person would last until their scream ended and they had to inhale. Air that hot will cause the water in the lung tissues to quickly vaporize, essentially causing a small explosion in the chest. The body would boil/burn away, and the nonflammable parts would be reduced (in both senses) to ash, mostly calcium oxide.