There is also an excellent discussion on water temp in the
"Color Guide To Steelhead Drift Fishing" by Bill Herzog
and
"What Fish See" by Colin Kageyama

Basically as you would expect as temp increases, the fish become more aggressive because they are cold blooded.

So techniques can change too. When cold use bait and lots of scent and make sure you cover all the water in a run because the fish wont move much. When the water is really cold, the fish will seek out warmer water and tend to stick to deeper pools.

In warmer water they will chase after hardware, and move farther to chase your offering more aggressively. The fish will tend to seek out more rapidly moving water, ie riffles and breaks. Too warm and the fish will seek out the water with the most oxygen.

Color preference seems to change with the temperature also. -- red/orange in cold and blue, white, black, etc in warm.

There is a lot more to it and you need to consider water clarity, water depth, and amt of light hitting the water just to name a few of the variables.

Hope this helps a bit.