You can easily find pads without the two hour shutoff....I know this to be true as I, and many others here, have do e so and use them exclusively for brooding chicks.Heating pads turn off after 2 hrs and at 4 weeks they should be kept at 80.
5 degree drop weekly. Of course they will be fine and chicken people worry too much so my suggestion is to sooth your soul and give u hope ;-)
Rice is a great heater. Put dry uncooked rice in pillowcase or small cloth bag about size of gallon ziplock. Microwave for about 2 minutes and immediately wrap with towel and place into place u have them.
If very hot and wrapped with towel, I have had a rice bag last 6-8 hrs. You could do a couple and place at the end of each container.
Save rice and repeat. I use for myself on sore muscles. Works great. You can also use dried beans but rice is softer and seems to hold heat longer to me.
At 4 weeks, even following the outdated and rather incorrect 90-95 minus 5 degrees per week "rule" the birds would not be at 80 degrees. My 4 chicks are brooded outdoors (daily temps ranging from high teens to 40) and at 4 weeks are selfweaned from all supplemental heat, and this experience is not unique, it is actually the common observation of folks brooding outdoors and allowing self regulation.
