Created attachment 147289 [details] temp See the attachment. The visual representation shows a full graph, despite the low temperature. That not indicative for the relative temp.
It looks like temperature doesnt have a maximum on your machine. Unfortunately there's not much we can do do to get one. You could set a maximum manually but unfortunately horizontal bars doesntz allow to do that. Changing this bug to track that.
*** This bug has been marked as a duplicate of bug 479573 ***