Here's a quick script:
$*SCHEDULER.cue({
my $so = qx{sensors};
my $m = $so ~~ m:g/^^ Core \s \d+\: \s* \+(\d+)/;
$m.Array.map( *[0] ).gist.say;
}, every => 1);
sleep 10;
Unfortunately, you need the lm-sensors package, and the sleep command at the end. If someone has a solution with less processor impact, then I'm all ears.
Will turn this into a GUI, soon.