Yep. 19 chicks.For some reason, the computer is eating my posts, so, here goes again. This is a wonderful addition to the brooding tool box. It doesn't have to be an either/or approach when considering MHP vs WH. IMO, in my zone 4 area, I'd start with MHP, and graduate to WH, perhaps building an insulated box, using a box within a box with a layer of insulation (even newspaper would work) or using an old cooler upside down, door removed with a cave opening cut on both long sides, with duct tape sealing the exposed styrofoam. Exciting that it holds heat so well for chicks at 3 days old. Margaret, how many chicks???
I think mass is key to this no supplemental heat method. I know that hatcheries won't send out fewer than six chicks. That's probably the minimum number.
Here is how they were doing about an hour ago. It has begun to rain a bit, and they do have a tarp over them at the moment. I'll check on them in a bit, but I don't hear panicked chirping so they're probably OK under the tarp in the rain.
EDITING to add that I will be giving away all the cross breed chicks tonight or tomorrow. That will leave me with about ten chicks. This could change the thermal math pretty drastically.
Also, although they are outside, they're also about teen feet from my open living room window. If they are in distress I'll be ale to hear it and respond right away.