Chickens Start at time stamp. The rest of the vid is offtopic.
I tried a dozen different scenarios and this produces by far the most eggs.
youtu.be/Q5E6GeGGc0Q?t=91
A fire behind the coop was destroyed after enough eggs were hatched.

Move them nearer.

Make sure the fire is covered so it doesn't go out in the rain.

And, obviously, make sure it's always got fuel.

The eggs would be in the fire if it wasn't for the fence in the way. I also tried leaving them there without any buildings in the way and nothing.

What biome is your base in?

Originally posted by Mr B.:

What biome is your base in?

meadows

the is trick to have the chickens covered by a roof. i have a 3x3 fence and they get warm even on the furthest point from the fire.

Originally posted by Frosty:

Just like the title I have a small set up campfire set up in a fenced enclosure with the eggs on the ground nearby. They just keep saying "too cold." Do I need to build like a proper indoors hen house or something?

As long as you have shelter & fire (so a house or any structure with a roof) and keep the fire steadily lit so it doesen't intermittantly extinguish & reignite, keep the eggs on the floor.

Once the eggs are on the floor, wait a few seconds: they will go from ''too cold'' too ''warm'' when the right conditions are met. Also pays to barricade your fire off from the eggs, so they don't accidentally hatch in the fire & die right away.