You might check out the Medline lace-up wrist splint. I have a drawer full of splints I tried before I finally found it (including neoprene, which did make my hands/wrists sweat).

It is lace-up canvas with flannel lining, and is more breathable than other varieties. It has an aluminum spoon to keep the wrist stationary, but it can also be removed. The lace straps pull to tighten, then attach to velcro, so they are very easy to fasten one-handed.

I find the design makes it really easy to still a computer - numeric keypad and all. When I was still able to drive, I even used them for driving.