Subject: Is there a heat coil equilibrium point?

I wish to construct a heat coil that reaches and stays at a temp. of 160 deg C. 
I was wondering if this is possible, and if so what equations I could use to 
help figure this out, I know that h = (i^2)rt, but by this equation the coil 
will continue to increase in heat over time.  However, I see coils heated for 
extended periods of time and they don't melt, so I assume at some point an 
equilibrum occurs.  If so how can I set that Equilibrium temp?  I would prefer 
to use DC since AC varies slightly depending upon your outlet, unless this 
change wouldn't matter.

Re: Is there a heat coil equilibrium point?