Do you have time to get a YF vaccine?. It lasts for a lifetime. and then you can go somewhere better to sleep for your stopover.

I was based in NBO most of last year, and you really can't move around Africa without one.

Not sure what ticket you are on, but the KQ lounge at NBO is actually quite nice, apart from the dreadfully slow wifi.

I haven't stayed there, but the Four points is super convenient and looked very modern and comfortable when i was driving past.