Hey, glad to hear some are doing well! Most of us use a heating lamp to brood, a heater isn't good because it has drafts, and yours turns off sometimes which you discovered isn't good :/
You could do two heat lamps in case one breaks. Some people do a special heating pad setup or they have the brooding heat plates that the chicks go under for heat.
Especially if the chicks are wet/damp, drafts are not good :O
You have 23% game bird feed, I am thinking its layer and not grower? 23% is ideal for laying hens but chicks need a bit more, some people use UNmedicated turkey feed if that's the only thing with a high protein percentage around them.
There was another poster several weeks ago that was feeding them about 20% protein? and at about three weeks feathering time, they became cannibalistic, pecking each other until there were wounds and blood so keep an eye on them/consider upping the protein until they're several weeks old