Hey Tom,
In my experience, heat does help but only through the form of showers and heating pads. Whenever i go on holiday or whenever it's summer time, my muscles go to pot and i become lethargic and sore. Although, i do seem to be able to move easier. This seems a good question which i think i'm going to talk to my specialist about.
from Paige
(Beckers)

Type of Myotonia: becker

Country: UK