Explanation for cold/warm switch in pid_loop

[elf02]

Can you please explain the warm/cold logic:

https://github.com/brycesub/silvia-pi/blob/54de21218dc9e02fe6c39871e92e28bcfc769846/silvia-pi.py#L152-L168

iswarm will always be false. Should the pid values for the warm state be set only once when avgtemp >= 100?

Thank you :)