So here is a new one i was thinking about last night as i lay in bed in pain......Does anyone notice the difference in pain when it comes to a dryer heat then to a damper heat? When I go to the valley where it is dry and in the 100's I get a lot of swelling not just my legs, feet and hands but my whole body, and the pain is just aching. But in the damper heat where i live i get less swelling with loads of pain and burning and my veins are way more painful.
EM is a neurovascular disease.
Cold will feel good, as it numbs any pain (nerves), but is contra-productive in the long run, as it further damages the circulation and thus the future drainage of the accumulated fluid. (That's why they advise strongly against any ice/ice water treatment.
The more the feet swell up due to the fluid, the more the pain will become dull (aching). Does unfortunately not mean that it get's better, but only that neural communication is then more compromised.
As soon as swelling subsides, pain may well become sharper, as the neurovascular system must work overtime to reduce the accumulated fluid.
Hence, outside temp does matter. Extremely hot as extremely cold is bad. Activity during these conditions is even worse, as one (cold) masks the symptoms and can cause longterm damage and the other aggravates the symptoms, especially , when paired with activity (upright, like walking).
Humidity is likely not that important a factor, other than the influence on sweating. The more you sweat, the more fluid you lose. But sadly our extremities, where the illness predominantly manifests, do not sweat much at all.
Just my two cents from a subjective point of view.