Cold heater

Bored cattle get into trouble.  Since the last few nights have had temperatures down into the teens, the water trough water freezes over.  So I dropped a stock tank heater in the tank, and before going to bed at night I plug it in.

This morning I discovered the water trough frozen over.  The cattle had lifted the heater out of the trough.  Why...?!! 

The heater element was cold.  I hope it didn't burn out.  I broke the ice and put the heater into the water.  It started to heat and melt the ice.  *Whew*

By the way, the cow with the limp still moves slowly and is still recovering.