[Proportional band help]

What if I set up two PID loops? Both works at same time but I take output value from one and when temperature reaches set point I take output value from another? Will this make system unstable too? I can take output value from first PID loop until temperature reaches set point -1°C, then use last output vale until temperature reaches set point+1°C and then take output value from another PID loop. 

[Proportional band help]

Hello,

I need help with PID control. Is it possible to make proportional band different around Set Point? For example Set Point is 70°C, I want lower limit to be 63°C
 (start of proportional band) and upper limit 74°C (end of proportional band).