Masks will inhibit optimum oxygen intake.
You can wear a mask as a tickler, but as a ticklee, I do not recommend it at all.
You may develop too much carbon dioxide in the blood.
This is what I would be worried about myself. With a mask on the oxygen intake wouldn't be enough for me while being tickled and I'm sure eventually I would pass out from the CO2 levels.
Masks will inhibit optimum oxygen intake.
You can wear a mask as a tickler, but as a ticklee, I do not recommend it at all.
You may develop too much carbon dioxide in the blood.