The above WD marketing information should be evaluated using the "
Failure Trends in a Large Disk Drive Population" feb-2007 Google's study.
(Cf Abtract) <...> Surprisingly, we found that temperature and activity levels were much less correlated with drive failures than previously reported.
(Cf Conclusion) One of our key findings has been the lack of a consistent pattern of higher failure rates for higher temperature drives or for those drives at higher utilization levels. Such correlations have been repeatedly highlighted by previous studies, but we are unable to confirm them by observing our population. Although our data do not allow us to conclude that there is no such correlation, it provides strong evidence to suggest that other effects may be more prominent in affecting disk drive reliability in the context of a professionally managed data centerdeployment.
Reading the study, I suggest trying to keep your drives in a 30-40°C frame
