Filtered against evil, Moriarty Hell, I'll leave this open for Loki...why I don't know
So, it's probably best if people aren't going outside unless you can defend yourself from these things. But if you need to, I'd recommend going in at least pairs and having some source of fire/heat at your finger tips. Unsure of how? Simple. Poor man's flamethrower: hairspray and either a match or lighter.