Forest fire smoke protection while exercising?

[Filliam H. Muffman]

cbelt3 wrote:
[quote=Filliam H. Muffman]
The only thing I can think of is too heavy and expensive. Get five or six portable oxygen concentrators (7 lbs each) all running at once..

Never ever ever put yourself on high oxygen without a doctors order and monitoring.
Excellent point. I didn't know that CO₂ buildup could be such a major issue.