23C is worse than 53C. It is worse to run them too cold than to run them too hot. The manufacturers take the thermal expansions into account, and the drives are meant to run hotter than 23C. This is an annoying myth because common users try to make them run as cold as possible.
Edit: Quote from Google and their huge pool of data regarding hdd life expectancy:
"The figure shows that failures do not increase when the average temperature in creases. In fact, there is a clear trend showing that lower temperatures are associated with higher failure rates. Only at very high temperatures is there a slight reversal of this trend."
See the huge amount of failures at the lower end of the scale?
