I know that the open window was a mistake. I know I should have installed some form of net or something like that. I will do this soon.
However, I wondered also if there isn't anything new in the fight against mosquitoes. A new life hack, a trap or spray that actually works, a sacrificial offering to keep them occupied or preferably something like this:
A few microphones (e.g. from an ultrasound distance sensor) that can triangulate the position of the mosquito and then use this position to direct a death ray of some kind (laser, microwaves, whatever) directly at the mosquito (without killing me if the mosquito is close).
There are also some things with blue light and fans, search Amazon for Katchy.
Bats and some types of birds are good but getting a bat or a bird could be a challenge. Depending on where you live look into the birds that eat mosquitos and provide nesting for them.
There was an interesting episode of Sliced Bread on BBC Radio 4 recently about mosquito repellants.
Basically DEET or PMD is as good as it gets, but applied incorrectly makes it ineffective. Citronella is pretty much useless.