;-)

heat.sh

#!/bin/bash

# target temperature
ttemp=22

# heating slope
slope=5

############################################

debug=

cores=$(grep -c ^processor$'\t': /proc/cpuinfo); : ${cores:=1}

heat () {
  ctemp=$(sensors | sed -nre 's/^[^°]*[+-]([0-9]+)\.[0-9]°.*/\1/p;' | sort -n | head -n 1)
  tdiff=$(( $ttemp - $ctemp ))

  echo -n "${ctemp}°C/${ttemp}°C"$'\r'
  [[ "$debug" ]] && echo

  [[ "$debug" ]] && echo Current temperature ${ctemp}°C, target temperature ${ttemp}°C, temperature delta is ${tdiff}°C
  if [[ ! "$tdiff" -gt 0 ]]; then
    [[ "$debug" ]] && echo no need to heat
    return 0
  fi

  for ((i=0; i<$cores; i++)) {
    [[ "$debug" ]] && echo "Spawning cpu hog #$((i+1))/$cores"
    while :; do :; done &
  }

  dur=$(( tdiff * slope ))
  if [[ "$dur" -gt "$ttemp" ]]; then
    dur=$ttemp
  fi
  [[ "$debug" ]] && echo heating for $dur seconds...
  sleep $dur

  while read line; do
    [[ "$debug" ]] && echo killing...
    kill %$(( ++job ))
  done < <(jobs -p)
}

while sleep $ttemp; do
  heat &
done

# licensed under GPL, Daniel Albers <[email protected]>, 20111229