Outdoor Acclimation

[BBZZZZTT]

Hey chicken people!
Yeah, this is yet another thread from a newbie who is probably overly concerned with moving my chicks outside.
So here's my scenario:
My chicks are 4 1/2 weeks old. Thus far they've been housed in my 55° basement with MHP, a non digital Sunbeam heating pad on medium heat.
I've read they should be acclimated to outdoor temps gradually even though they seem to be pretty well covered with feathers.
A couple days ago I took them out for a visit to the big coop (no other chickens). They were out for about 45 mins until they started looking cold so I brought them in. It was about 40°.
Today it is currently 43°. I set up their food/water and MHP on high so they could have a more extended period of acclimation time and warm up from time to time.
I introduced them to their coop, none have ventured out into the run yet which is fine with me since it's a tad breezy.

So here's my question.
How long should I leave them out here? I have a coop cam that I've been watching, but I'm a total newbie so not sure what I should be looking for in terms of signs of cold or trouble.
They SHOULD be smart enough to use the MHP if they're cold right?
How much daytime acclimating should they have before they can be outside overnight?

Tomorrow I am planning on leaving them out pretty much all day since it will be pretty close to their basement temp anyway.
Unfortunately though we have a cold front coming and night temps are still dipping low.

Attached is our weather forecast since I'm a visual person and that's easier than trying to describe our fluctuating temps.

Here's my coop cam from a few mins ago

And here's a bonus chick pic!

 

[ChickenCanoe]

If you have electricity out there and they use the MHP, I wouldn't worry about them. They should be out around the clock. The fresh air will do them good.
A mother hen can easily raise chicks in those temps. All she does is provide a warm spot and lots of cool space. That's what your MHP is doing.
Even adult birds need acclimation time. They're not happy when cold fronts move through dropping the temp from 70 to 20.

 

[BBZZZZTT]

If you have electricity out there and they use the MHP, I wouldn't worry about them. They should be out around the clock. The fresh air will do them good.
A mother hen can easily raise chicks in those temps. All she does is provide a warm spot and lots of cool space. That's what your MHP is doing.
Even adult birds need acclimation time. They're not happy when cold fronts move through dropping the temp from 70 to 20.

Even with the drop from 53 to 20 tomorrow night?

 

[ChickenCanoe]

Is your MHP working out there?
I've had hens hatch chicks at 20F
They just need heat, regardless of the ambient temperature.

 

[BBZZZZTT]

Is your MHP working out there?
I've had hens hatch chicks at 20F
They just need heat, regardless of the ambient temperature.

Yep it's on. I also bumped it up to high.
They are under it currently warming up.

 

[ChickenCanoe]

They'll likely move in and out during the day and hunker under it at night.
If they never leave it during the day, they're too cold.
I find that chicks hatched and raised in cooler temperatures - provided they have a warm place and proper nutrition - feather out better than those kept cozy warm 24/7.

 

[BBZZZZTT]

They'll likely move in and out during the day and hunker under it at night.
If they never leave it during the day, they're too cold.
I find that chicks hatched and raised in cooler temperatures - provided they have a warm place and proper nutrition - feather out better than those kept cozy warm 24/7.

They were just huddled under for a while but now they're out and about