Use clean, fresh water when making ice, since you will often be drinking it later.
As water freezes, it expands, taking up some more space.
Comfort from ice
Ice can make people more comfortable. It creates a pleasant coolness in food and drinks. It can also help heal injuries and reduce the pain from them. Applying ice can temporarily numb the pain and help reduce any swelling. Warning: Ice or an ice pack applied directly can be harmful to the skin. So, wrap it in a cloth before holding to the skin.
Problems from ice
Ice on the ground or sidewalk can cause a slipping risk to people walking, riding or driving on it.
Also, when water gets in cracks in pavement, roofing or walls and then freezes, it expands and can make the cracks larger. Water in external pipes or even internal pipes that are near the outside or when the heat is turned off can freeze. When it freezes and expands, it can damage the pipes.