Heat/Burning play advice?

[Katv]

My super vanilla husband is slowly getting into his kinks and one we’ve discovered is that he enjoys a slight internal burning sensation when I finger him. And so far, the only things I’m aware of that cause the burning eyes likes are: tooth paste, icy hot, and ginger.

Does anyone have any advice for us? Is there anything we can use that’s in between those levels of heat, or would we just increase the amounts of whatever we use?