I just got back (I go periodically because my daughter lives there as a student) and I had a rather unusual week. I always have about a 5% improvement after being on the island for a few days. My daughter knows my limits, and is very cautious with me, but we usually end up walking all of Waikiki after a few days (with stops to sit on the way). But this time, she decided she is done with dorms and traveling back and forth between Seattle and Honolulu, so her and a friend got an apartment. Sooo, of course mom is stupid and says "of course I'll help!" By the time the moving in part started, I had all ready been there a few days, and stamina was returning. We shopped for pots and pans. We shopped for a bed. We shopped for this and that. We cleaned. We cleaned some more. I was pushing myself hard, and knew it. She knew it. But I never got sick. I started to twice, felt the sore lumps start in my throat, but then it would go away. So here are my theories? First, I know MCS and allergies is a huge part. My nasal allergies reduce while I am there, and it comes flooding back as soon as I get to the airport and smell jet fuel. Then my legs turn to jello, I get vertigo, my brain doesn't work right, and I plain and simple look/sound drunk. Thank god for wheel chairs! Second, natural vitamin D. Pills make my blood labs look better, but I never feel better. I do think natural vitamin D from sunlight works better for me, although I don't get "better" in Seattle summers. Third, which ties to #1, cleanest air in the US. Although I live two blocks from salt water, I think the salty air is much stronger there (for obvious reasons). Fourth, heat. Although, once again, I don't feel better when Seattle gets into the 80's? And Last, not waking up to an alarm every day, but waking up naturally. And to sum up, due to how much I over exerted with no PEM, I actually think my improvement was at least 10%. I would have ranked myself at 75%. Maybe even 80%. I know there are Hawaiians with ME/CFS on this website, so Hawaii is no cure. But why on earth do I feel so much better there? Anyone else have this drastic of improvement from travel?