Pretty much, I downloaded the full pdf and had a quick read. It also said that while they ran better hot, temperature was actually a smaller factor in disk failure than had previously been though. Kind of annoying as I read it after I bought 4 Zalman heatpipe coolers..
Google's use of terminology/temperature categorization is very unfortunate, because what we consider hot, is not quite what Google thinks is hot, and this has given rise to this unfortunate meme that temperature don't matter and HDD's like to run HOT, which is not really accurate or the full story.
To clarify: While they state that moderately high temperatures don't seem to affect drive mortality that adversely, they do in fact state that the mortality rate does changes significantly for the worse at "the high end of our temperature range" particulary for older drives (which is broadly in line with my own experience over many years.) What most people fail to realise/mention, is that Google considers anything over (only!) 45C "high end".....! Furthermore, 3 years and over is apparently classed as "old." I've got several drives in my system now that are older than that. Many home PC's have hardware that's even older...
Steve Gibson of Spinrate fame also makes the point about the Google article that many drives in fact encounter, to use Google's terminology again, "high end" temperatues in just normal home PC use (and we see so frequently on this forum as well), so the conclusion that most people seem to read into their results (which is "don't worry about your hdd temperature") is just wrong.
On the contrary what they say actually underscores that you should keep an eye out and keep your temperatures below 45C. So: moderately hot drives are ok, extremely hot (>45C) drives are not.
Aside: from the graphs it appears to me that 35C-45C is the ideal range (It contains the 2 the article bands with the lowest mortality in the majority of the age groupings.) Going outside this range on either side increases drive mortality. Interestingly enough, for younger drives, running them lower than 35C is more risky than above 45C, while for older drives (3+ years) below 35C is substantially less risky than above 45C. (In fact even less risky than 35C-45C, perhaps <speculating> because by then the drive is nicely "run in", and the true effect of heat and expansion plays a bigger role in failure than when the drive is younger.) Anyway, this is all just interpreting the graphs in the Google article, so if you don't believe me look for yourself.
I also quote some relevant paragraphs from the article:
What stands out are the 3 and 4-year old drives, where the trend for higher failures with higher temperature is much more constant and also more pronounced.
Also they say:
Overall our experiments can confim previously reported temperature effects only for the high end of our temperature range and especially for older drives.
In the end, the bottom line is IMO that manufacturers put a maximum operating temperature on their drives. They do this for a reason. You wouldn't expect your car engine not to suffer shortened life or other ill effects if ran beyond it's rated redline permanently, so why expect it of your hdd?
Edit:
As for the op's original question, yes HDD's have a minimum operational temperature too, so in they can in reality be too cold. In practice I wouldn't worry about it as it's unlikely that your drive will be too cold unless you run your PC inside a walk-in freezer or something.
Aside: In Google's study, the worst mortality rate for "cool" drives were for drives 0-3 months old, and their coldest temperature range was 15-30C. Even then the mortality rate in that range was still only roughly half of the maximum measured mortality rate, which was for running a 3-4 year old drive >45C. For all the other age groups (e.g. 3+ moths), the 15-30C mortality rate is also substantially smaller than for 0-3 moths, and by 3+ years old it is in any case exceeded by the mortality rates of drives running at 40C+. (So it's more dangerous by year 3, to run your drive beyond 40C than it is to run it between 15C-30C.)
