Like Eldartford says, heat will not be a factor unless you have some very unusual system, giant Krell amps always on along with an older massive projector system, and a small stove, etc.
However, imo the 10 guage is the superior choice for the reason stated by Rushton.
Some will say the difference is not significant; but, as Keith Johnson of Spectral Audio has stated- its the sum of many small improvements that can result in a significant advantage. The 10 guage of the same quality wire will provide reduced impedance to the current flow, and that is desirable for amplifiers in particular. I would suggest the 'quality' of wire is just as, or more, important as the difference in guage. There is much higher quality wire used in robotics for example, with very significantly better shielding/grounding. I would examine that option as opposed to simply larger guage. Good luck & happy listening. Pete
However, imo the 10 guage is the superior choice for the reason stated by Rushton.
Some will say the difference is not significant; but, as Keith Johnson of Spectral Audio has stated- its the sum of many small improvements that can result in a significant advantage. The 10 guage of the same quality wire will provide reduced impedance to the current flow, and that is desirable for amplifiers in particular. I would suggest the 'quality' of wire is just as, or more, important as the difference in guage. There is much higher quality wire used in robotics for example, with very significantly better shielding/grounding. I would examine that option as opposed to simply larger guage. Good luck & happy listening. Pete