Speaking of last year, I remember you had trouble with newly-arrived chicks and heat plates.
I was looking through Cackle Hatchery's page of policies, and found this bit very interesting:
"
MAIL ORDER CHICKS REQUIRE HEAT BULB NOT HEAT PLATE
"Mail order poultry is entirely different than poultry hatched out in an incubator at home or under a hen. Mail order poultry require much more heat initially for the 4-7 days than a heat plate generally can provide. Mail order chicks need their body temperature rapidly and immediately and artificially warmed up to 104 degrees (which is a mother hens’ temperature). Most heat plates do not do this. The chick does not have the ability to generate enough of its own heat immediately on arrival and sustain its own temperature. About the time of arrival, the chick is losing it’s (mother nature protection). Generally, after the first 7-10 days of using a heat lamp you can switch to a heat plate that does not put out any light so the chicks can adjust to a more circadian rhythm."
https://www.cacklehatchery.com/guarantees-policies/