Cold snap surprise death

[electrycmonk]

This morning our Gray Momma, a Jersey Giant was dead, in the corner of the coop. No unusual behavior from her over the last several months.

I did check as I picked her up from the floor of the coop, did not feel egg bound. Put her on the scale, 5.5lbs & she's been dead a short time as stiffness had not set in at 8AM-ish.
The last few nights we had a cold snap roll in but, I have been very cautious about keeping plenty of unfrozen water with easy access. Last night was the coldest ~22°F and the coop stayed mid 20's with no draft to speak of....
Everyone else seems fine non-the-less.

I put her in the freezer a bit ago. I don't currently have the space, tools or mindset for post mortem or processing for food status.

The flock had fowl pox about 6-7 months ago and she had the facial scabs but, no where nearly as bad as a few others did and everyone else is fine still.

I'm curious if anyone would have any viable theories -logocal ones mind you- of cause for death like this?

I've tried to clearly give all valid triage/forensic data points...
Thanks for your time and consideration for reading and possible thoughts in replies.

 

[JacinLarkwell]

We've had birds freeze to death, but in -15 and lower, not 22.

 

[Chickensandhorsesforlife]

Hmmm. so weird. I have lamps in my coop for all of by birds, but i do not think that 22 is deadly