My numbers are a little extreme with the pulley size I'm running now, but let'* use idle as an example.
At idle, the SC wants to run 120-140. Your coolant is what, at least 185? The coolant will heat it up at idle. Under load/use/abuse, the SC temps can spike to well over 200, but the coolant can only cool it later to the coolant temp, whatever that may be. The coolant WILL cool it down to a point, but not beyond that.
The SC is aluminum and has cooling fins (small, but they're there). I'd shut it down and pop the hood for a few minutes if you're concerned. Or install hood vents.
Also consider a high-speed fan override. Many of us have.