You could use a SATA to eSATA bracket to then allow you to hook the drive up externally. You then put the drive either in an external eSATA enclosure that has its own fans or use an external drive dock that might be cool enough with the drive "out in the open" or even blow air from a desk fan on it.
Example SATA to eSATA bracket (there are also version with two eSATA ports):https://www.amazon.com/gp/product/B000GX4C7I/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1
Example of drive dock with eSATA, USB 3.0, and Firewire (cheaper options are out there, but this is a brand I use and trust...you can also get models that can handle two drives):https://eshop.macsales.com/item/NewerTech/VU3ESFW8/
I won't offer an example of an external enclosure with a fan as they are pretty self explanatory.
I regularly use an eSATA bracket with my old Windows desktop and have one on order (arriving tomorrow) for my new build that I just finally got around to actually building (I could not find my spare brackets). It also fits you need to wanting to disconnect the drive at times.
Beyond that, an operating temperature of 45 deg C is well within operating specs for a WD Red. Here is the spec sheet:https://www.wdc.com/content/dam/wdc/website/downloadable_assets/eng/spec_data_sheet/2879-800002.pdf
You can see that upper operating temp per the spec sheet is 65 deg C, so you are well below the upper limit. To me, this makes sense. These drives are designed for use in NAS devices, which typically are multiple drive NAS devices. When you have multiple drives operating in close quarters like that, one can assuming that they are going to run a bit hot compared to a single drive operating all by itself. So, I would assume they design these drives to handle those higher typical single drive operating temperatures.