I agree with Chuck Hawley, the problem is where the heat is being generated, or more precisely, the high resistance area is generating heat. A properly sized cable shouldn't get hot, or even warm.
I bought a 16 ton hydraulic crimper with 11 sets of dies on Ebay for $34, best $34 I've ever spent, aside from a few weeks in Subic Bay. It makes fantastic crimps! I'm in the middle of installing a 1200 watt
solar panel setup on a friend's yacht and we're using
boat cable, closed end tinned lugs and
adhesive heat shrink to make low loss (4/0 cable) connections to his
batteries and bus bars, in addition to the 4 AWG cable from the
solar controllers with less than 5 ft runs. We spent $600 on cabling, but you only have to do it once if you do it right.