The ones I have here run pretty much "cold". But they also can tolerate much more heat than a mechanical drive, which is important for notebooks and empeg installs.
The electronics are generally spec'd for up to 75C, whereas a mechanical drive normally says 50-55C.
Most SSDs say 0.5W (or less) when idle, and ~1W when "active". Mechanical drives usually are in the 2-2.5W "active" range.