In an informative answer suggesting that wheel bearings could be the cause for road drone/hum noise, no mention was made of heat.
In another nice answer I learned that bad/noisy bearings generate their own heat.
If noisy bearings generate their own heat, can we not determine whether bearings are the issue, and which wheel it is, by simply touching the rim after a bit of driving?
With disk brakes, even a very slight snug disk generates so much heat that a short trip means the rim is so hot one burns one's fingers if one touches it.
Do failing wheel bearings generally generate heat substantial enough that one would feel it with one's hand? Even a little bit of heat means that there would be a basic test for determining not just that wheel bearings are indeed the issue, but also which wheel it is.