Hi everyone. New to chickens. Started with 4 day old chicks and 2 died of what I think may of been coccidiosis very sad and had to bury them. It's a heat wave here in Queensland over the past 2 weeks and I've heard this could of contributed to them passing away? The other two are now 3 weeks old and are sitting on their perch most of the time, eating, drinking too. One has some diahorea, it's has normal poop in it but a bit of runny pale brown stuff too. Should I be worried about her dying like the other two chicks?