I've seen the plastic connector melted quite a few times but sounds like yours is fine.
One thing to check, if possible, is the amp draw of the blower motor. If it's excessive, the switch could get hotter than normal. Take a look at the connector at the blower resistor also, just to be sure but even if it's loose or melted, shouldn't affect the switch though.
Throwing out random things that can cause excessive heat is all.