1994 Chevy Caprice battery cable

Recently I was having charging issues. Voltage meter running down to the orange part of the gauge, ect. I changed the battery and alternater. Turned out the cable coming off the battery goes to a bolt connection next to the fuse box which is near the passenger side windsheild. This connection was loose, causing it to arch and generating enough heat to partially melt the plastic bolt cover which sits on top of the bolt. Well, the connection was tightened and now runs normal and the voltage meter seems fine.I do notice that the bolt still can at times be pretty hot to the touch. Sometimes enough that you can only touch it for aq second. I guess I'm trying to determine if this is normal. I realize it should get warm, but how hot does it have to get before it would be considered not normal? Any help would be great. Thanks