I live in sunny San Diego a few blocks away from the beach so there isn't a drastic change in temperature between day and night. My chicks just turned 5 weeks and yesterday I built them a run outside. It's 5ft by 3ft and half chicken wire, half plywood so they have shade. I didn't build an actual house for them like my other chicks since this is just a temporary structure til they're old enough to go with the others. The lowest the forecast is for the temperature at night is 63...do I still need them under a heat lamp. I put one in there last night but I'm not sure if it was necessary and don't want extension cords throughout my yard unless needed.