Generally the reasons connections get hot are loose or poorly crimped contacts on the psu side or, of course, trying to pass more current than the design limit. The only solution for poor crimps on the PSU wires is to RMA the PSU. If the contacts have loosened thru thermal cycling you can tighten them thru the careful use of a pair of small, flat bladed, jewelers screwdrivers. Use one to hold one side of the contact steady while pressing in gently on the other side with the other. You could also use a contact enhancer like Caig Labs Pro Gold.
. Also make sure you are using the P4-12V connection (4-pin square) if it is available as it will take a lot of load off the ATX connection. If your PSU lacks the connector, adapters are avaiable to use drive power connectors.
.bh.