My wife has been badly bitten on recent trips by mosquitos usually ending with bad blisters then scarring. We have used the plug in repellents to some effect but I am unsure if we are using these things correctly. So a few questions for our mosquito experts. When you plug in these deterrents when asleep should we also leave a window open? I am a bit concerned that we are breathing in something toxic? Is it sufficient to only plug them in at night or should we leave them plugged in all the time? I have got a lot of info from Googling but any other first hand tips would be appreciated.