Sounds like a load of shit to me
Never been told this. I got a tan last summer and it didn't affect it whatsoever. I actually got severely burned and had blisters all over my back, legs, and bum
It hurt like all hell, not even pain killers helped much. Just a reminder, if you are tired, as a lot of us probably are, do not fall asleep on the beach!
The only thing I think could be a problem is if the blisters got infected and they were actually around/on the fistula.