We have a hot tub. We use Bromine ( not sure of the spelling) in place of Clorine. It is so relaxing and soothes my pain
I sleep better now because is relaxes my body.

A lot will depend on how the spa is kept clean and how much chlorine is used. Some people with COPD react very badly to chlorine, and if you're one, then the spa won't be comfortable for you. If you can tolerate the chlorine, then have at it. The warmth does wonderful things for your body and it won't make any difference to your COPD. The humidity might get to you, however, so watch for that, too. If you can manage the chlorine and the humidity, enjoy!

If anyone is a cardiac patient, do not use the whirlpool or anything close to it. Ask your doc.

Hope it helps you!!
Would like to know how it does for you. ..
Breathe easy...

We have a hot tub that i use quite frequently. Once in a while it bothers me and when it does i get out and stay away from it.
We don't use chlorine. We use bromine in ours.