Linux thermal monitor & emergercy shutdown

linux_thermal_monitor.sh

#!/bin/bash

# http://www.raspberrypi.org/forums/viewtopic.php?t=30670
#temp=`cat /proc/acpi/thermal_zone/THRM/temperature | cut -c26-27`
temp="`cat /sys/class/thermal/thermal_zone0/temp`"
let tempint=$temp/1000
tempfloat="`bc -l <<< \"scale=2; $temp/1000\"`"

debug="$1"

if [ ! -z "$debug" ]; then
  echo "debug: temperature=$tempfloat degree"
  #exit 1
fi

dat=`date`
mail="`which mail`"
notifyuser="root"

alarm_temperature="64"
switchdown_temperature="70"

if [ "$tempint" -gt "$alarm_temperature" ]; then 
  if [ "$tempint" -gt "$switchdown_temperature" ]; then
    echo "<$dat> $tempfloat degree: temperature too high! Shutting down..." | $mail -s "Emergency shutdown" "$notifyuser"
    if [ ! -z "$debug" ]; then
      echo "<$dat> $tempfloat degree: temperature too high! Shutting down..."
    else
      shutdown -h now
    fi
  else
    echo "$dat at $tempfloat degree" | $mail -s "thermal alert: $tempfloat degree" "$notifyuser"
    if [ ! -z "$debug" ]; then
      echo "$dat at $tempfloat degree"
    fi
  fi
fi