No problem whatsoever.
Some times the heat will have a subtle effect on the level of gloss, which in turn can have a subtle effect on the appearance of the tone, but that applies to untoned pints as well.
When I tone my prints - usually RC but sometimes FB - I make it a practice to use a hardening bath before the final wash. There probably isn't as a great need to do that, because modern paper emulsions are quite robust, but toning does make even them at least a little bit more prone to physical damage. Heat can accentuate that vulnerability.
I just use the little bottles of Part B hardener that ship with Kodak Rapid Fixer. They need to be diluted 1 + 13. I have no idea what the print capacity is for that mixed solution.