Spinal Fusion/Back pain?

Today I was in my car listening to music for about an hour with all of the doors/windows up. It was mild day, but not warm or hot, but inside of the car it got sort of warm. Then I starting sweating and my whole body especially my hands got wet. Then we had a BBQ outside in the backyard and I ate outside too. It was a little breezy outside and got sort of cool. Also we have a swimming pool in our backyard and maybe that's why it was cooler than expected. Then I went to the bathroom and it was cold in the BR. When I was done, my back (left shoulder blade) started feeling pulled with a little pain until now. By the way I have Duchenne's Muscular Dystrophy, 17 1/2 years old male, use a power wheelchair to maneuver around with, cannot stand/walk/jog/run/crawl, limited movement in arms. I've had three surgeries and one procedure done, (2 heel cord surgeries/1 spinal fusion rod implanted/1endoscopy. Yesterday I also heard a cracking sound, but did not feel anything. Do you think the cracking sound was from the rod? Or am I being paranoid? Lol.