I'm a newbie and do not have the knowledge of people who have been doing this for a long time, I hope you get good response to your question because I've been wondering if I have it too.

All I've been able to find for secondary erethromelalagia is to treat the underlying cause ie SFN, and to try to keep your feet cool. Heat really triggers mine, I can't wear shoes in the house and I've been sleeping with my feet poked out from under the blankets for 3 years. Mine is better in the winter, cold doesn't trigger my symptoms like it does some here, its a relief. Trying to soak them in cool water doesn't work though, it hurts when they warm back up. Thats probably because its a vascular problem but I don't really know.
It seems like a lot of hot weather seems to make it trigger more easily, I can only imagine what you must be going through in Georgia. To me it seems like the more I can keep them cool the less likely they are to flare up when they are exposed to some heat.

I hope someone has some better info, I'd like to hear it too.
Zygo