I don't have RSD/CRPS , but I've had treatment with an infrared product, LED & also a Low level laser{LLLT}.
- for my muscle pain the low level laser was much more efficient - faster & worked better for pain relief.
I use an infrared heating pad at home.

If you can get a short test session with one or both to see if either type works for you I would give it a try.

neither type should put out very much heat at all.

you should be able to ask that they don't push or apply any pressure to your skin if it is very sensitive, it doesn't have to touch you to work.
they should be able to hold it close but not touching you for the treatment.

LLLT would only take about 20-30 sec for a area, while infrared or LED light would take 10-20 minutes + per area. {approx. avg times for muscle pain}