More often than not lately, when I turn on the cold water anywhere in my house what I get varies from warm to steaming hot. I just realized that the hot water is also flowing into my toilets as well. It takes anywhere from several seconds to a few minutes for the water to cool. I have a new fridge with water access & an ice maker. I don't know if this problem will damage it, not to mention the wasted water. Any ideas what is causing this? I don't know how old the water heater is, haven't lived in this house very long. Thanks for your help!

Do you have a hot water recirculation system? That is the first suspect in the list.

Somewhere...... somewhere in your house, you have a cross connection. Check valves in the water system usually prevent this from happening. It could be anywhere where hot and cold are blended together, like a mixing valve. When a check valve fails, it allows the greater pressures from hot water to force itself into the cold supply. Neutralize the system and begin feeling the pipes as they get warm and then work backwards. Also check your heating recirculation line, as suggested