Hi,
The main difference between an (SS)HD and an SSD is that it doesn't have moving parts inside.
Because of that, SSD's will always be much cooler compared to an SSHD or HDD. But since the heat disposal and the cooling options of a notebook are limited, it will always be hotter than a traditional PC for example.
But I've done this kind of swap so many times with a lot of different types and brands of laptops, I can assure you; Under normal circumstances, heat won't be an issue