krun: run command within temperature window
    
The command:
  krun 80 60 make test
will run the subcommand 'make test' while monitoring CPU temperatures;
if at any point the temperature goes above 80C, the subcommand (process
group) will be suspended until it falls below 60C, then allowed to resume.

^C will be propagated to the subcommand before krun exits, but only when
the subcommand is not in the suspended state.

I'm not sure how portable the sensing code is, please test in your own
environment before relying on it.