Leaving mine on low results in a temperature range of 30-39 depending on how hard I access it. This range has been constant for a year or more as I log the temperature every hour.
Sun, 10 Apr 2011 14:00:03 EDT NAS 192.168.1.40:81 Size:0915GB Free:0516GB [56%] Temp:32°C Up:19 days 0 hours 11 minutes
Sun, 10 Apr 2011 14:00:03 EDT NAS 192.168.1.41:81 Size:2748GB Free:1245GB [45%] Temp:31°C Up:19 days 0 hours 11 minutes
Sun, 10 Apr 2011 15:00:03 EDT NAS 192.168.1.40:81 Size:0915GB Free:0516GB [56%] Temp:33°C Up:19 days 1 hour 11 minutes
Sun, 10 Apr 2011 15:00:03 EDT NAS 192.168.1.41:81 Size:2748GB Free:1245GB [45%] Temp:31°C Up:19 days 1 hour 11 minutes
Sun, 10 Apr 2011 16:00:03 EDT NAS 192.168.1.40:81 Size:0915GB Free:0516GB [56%] Temp:32°C Up:19 days 2 hours 11 minutes
Sun, 10 Apr 2011 16:00:03 EDT NAS 192.168.1.41:81 Size:2748GB Free:1245GB [45%] Temp:31°C Up:19 days 2 hours 11 minutes
Sun, 10 Apr 2011 17:00:03 EDT NAS 192.168.1.40:81 Size:0915GB Free:0516GB [56%] Temp:33°C Up:19 days 3 hours 11 minutes
Sun, 10 Apr 2011 17:00:03 EDT NAS 192.168.1.41:81 Size:2748GB Free:1245GB [45%] Temp:31°C Up:19 days 3 hours 11 minutes