I have three 6-week old ducklings that I'm ready to have outside full time. I'm in the Salt Lake City area of Utah. Today the high was around 60 and they were in their dog kennel all day without any heat source. Tonight the low will be around 45. Is this too cold? Later in the week it's supposed to be high 45 and low 35. What do you think? And here they are playing on the grass today so you can see how feathered they are.