Do snowmobilers use the lake as a trail near your steps? Some bubblers make the ice unsafe for a lot larger area than is required. You need to put a sign in the area to show it is unsafe. Some people use a red light as well. If its a heavy snowmobile area, think about how you can protect your steps while minimizing the melted area.
Oh - and thanks for bringing this up on a 90+ degree day. Talking about winter helps to take the edge off a bit.
