Yeah, that was probably the problem as from the pics it looks like you get a lot of air in that pen. Mine are open like that too and they work great for summer time.... but not so good when it's cold.
This is why I keep enough tarps to cover every pen as reguardless of their age if they get too cold they will pile and it doesn't matter if they are day old or 8 weeks... someone always has to be on the bottom.
Good luck, I bet the test results come back negative for anything major... maybe some coccidiosis but if it's that cold in Maine I doubt they will even find this. Better to be safe than sorry.
This is why I keep enough tarps to cover every pen as reguardless of their age if they get too cold they will pile and it doesn't matter if they are day old or 8 weeks... someone always has to be on the bottom.
Good luck, I bet the test results come back negative for anything major... maybe some coccidiosis but if it's that cold in Maine I doubt they will even find this. Better to be safe than sorry.