yes, they can overheat because all the generator/alternator output is going thru them, but it's more a question of age then design and of folks upping the gen/alt size so the gauge is passing higher than design current, if yours is showing signs of overheating probably time to replace/rebuild it - some folks like to use a shunt on them, and some here have discussed using the volts gauge instead, but that's an appearance problem on the older trucks, and if the original 30/40 amp generator is used it shouldn't be a real danger when the wiring is tip-top ....
MAD electric recommends switching, pointing out the problem associated with age and upgraded alternators to handle a bunch on modern accessories
Bill
