You're correct, warmth is a sign of inflammtaion...but it can be subtle. Some people have joints that are burninig hot to touch, others just barely warmer than the rest of the body's temperature. Others even feel the heat & warmth "inside" the joint and really nothing objective such as heat to touch on the skin.
Going by warmth alone isn't sign enough of detecting inflammation. Warmth, even if subtle, plus redness & pain can equal inflammation of RA joints.
So you're saying tha your joints have no increased temperature? Are you having symptoms such as pain in the joints?
RA can be active yet the skin around the joint still can remain cool on touch.
Active/Severe Rheumatory Arthritis. Crohns. AS. Chiari Malformation & Right Brain venous anomoly. Partial complex seizures. Emphysema. Rheumatic Lung & Heart. MVP and Tricuspid prolapse. Had Lymes disease for 10 years.
Meds: Humira 40mg Q 4 days; Prednisone 20mg; Pentasa 4G daily; Imuran 50mg; Dilaudid 4mg; Diazepam 5mg; Avinza 60mg; Reglan; Antivert 25mg tid; LidoDerm; MiraLax & too many others.