rec or reg

Thought it was simply a dead battery last week - and it was, as tested and the fact that it boiled way when the bike ran - fitted new battery but charge over terminals when bike running was 13.4v - not enough to charge battery - took it out for a long ride tonight and lo and behold, boiling hot...

Cos I tested mine today with new battery. Battery sits there - 12.4v bike running at 5k - 13.4v (lights on) I had run the bike for a good 10 mile trip home and the re/reg was barely touchable! Too hot? On its way out? Normal? Fit a pc fan?

People Just a quickie. When your AT (RD03 specifically) is running, how hot does the rec/reg get?? I've never had any reason to check mine, but I was surprised that it was just a bit too hot to hold my hand on (the heatsink part) when the bike was running, but had no lights or anything...