River temperature, this is the best temperature because it means you are on the river.
Old Mil has the same properties as of all good river schwag that one would look for.
That is it tastes the same warm or cold.
Perfect temp is whatever it might be coming out of a drag-bag.
Now one important feature that I personally look for on river or camping trips is that from OLD MILLWAUKEE you usally wont have the post cheap-beer gas.
This is very important while camping in the close quarters of a tent.
On the con side of OLD MIL it cans are not as easily distinguishable in bag full of other beers so keep this in mind while digging in the bag for your favorite brew.
BEWARE OF THE MICROBREWS!!!