We have two beloved Rouen drakes. Here in Michigan the temps have been hovering in the single digits/negatives at night. We have a small enclosed duck house with a caged run. The door between the two is a towel, because they are terrified when we use anything else. The enclosed house where they sleep at night has a 125watt heat lamp that keeps the temperature roughly 40 degrees higher than the outside. Is this too warm? Does it "shock" them and make it more difficult for them to acclimate? When the outdoor temps reach the teens, we let them out during the day, but they stay close, sitting and shivering. Thanks in advance for the advice!!!!