My usually very healthy mother (no ME/CFS, etc) has developed a rash over her entire body the past two mornings. It's red and splotchy and warm to the touch, but not itchy or painful. It fades after a couple hours. She had a mild fever the first day during the rash, then a low body temp afterward. Her temp was very low today during the rash (albeit on antibiotics now, which can lower body temp a bit). She feels fine in the morning until the rash appears, then feels very wiped out for a few hours, but is pretty much back to normal by bed time. Nothing has changed with her daily routine or foods or chemical exposures. Yesterday she was drying her hair right before the rash appeared, and today she was doing mild stretching exercises before it appeared - so maybe heat is triggering the rash. She was bitten by her 100% indoor cat while medicating her three days ago, and the puncture wound did get red and lumpy on the first day, but is now fine. Cat-inflicted wounds can be pretty nasty, which is why she immediately went to the doc and was given antibiotics when the rash appeared afterward. We're on a small-ish island in the Pacific Northwest. A friend of my mother's that we saw last week (a coffee barista) also had a full body mystery rash when we were visiting, which looked similar. At the hospital yesterday, my mother met someone else she knew who was also there for a new rash. We don't know if their rashes did the disappearing-reappearing trick. So any thoughts on what it might be? Can something environmental or infectious cause these symptoms?