Growing up on Knoydart we always used Autan - that's the old school heavy duty Deet up to your eyeballs stuff. Works a treat, can't say it did me much harm but maybe I was lucky. Here's a run down of Deet related ill effects:
http://www.atsdr.cdc.gov/consultations/deet/health-effects.html
I think as long as you're sensible, not a child, not pregnant, and stop using it if you get any side effects - it is probably safer than a lot of people suggest it might be. But that's just my opinion.
I've never worn one of those net bags over my head - and never will either.
There's a new Autan stuff though, and it's deet free, organic and it works well, it does on me
cheers,
M