There is studies on the freezing of places. These are caused by unknown warlocks. The only way to know is to set your hand in mid air then on a table. Thin of freezing things that involve simple things like water and/or melted ice-cream. These may be regular muggle things but these are the only way of telling. If you ever grew up with your family and they are muggles then try these things. These are easier ways of testing. There are 3 types of these warlocks Evil, Non-Formal, and Formal. In the movie Frozen if you have seen it uses the Evil and Formal. You (if found an freezing warlock) can only have one personality. If you are found that you are an Evil there are some groups and/or books you can use for help. There are many things that can go wrong with your testing and I hope if you need help you find it.