No, I'm not human

You live in an unknown town in Russia with increasing solar temperatures during the day that can be deadly and at night there are entities called "Visitors" to know a guest is a visitor there are signs of perfectly white teeth, bloodshot/rapidly moving eyes, hairless or fungal armpits, dirty fingernails, insects in ears, and plus anomalies in aura photos (black patches) Visitors can k*** other humans and you are armed with a shotgun to kill all Visitors and before you let a guest in you peek through the peephole