Step 9: Addendum: Some Safety Precautions
1.) Neodymium is poisonous. Magnets are covered by a nickel plating that keeps the neodymium inside. Try to avoid handling chipped or worn-out plated magnets.
2.) Don't eat magnets, and keep them away from young children who might do so. It can be fatal for children to ingest 2 or more magnets because of possible pinching of the intestine.
3.) When playing with multiple neodymium magnets, always use eye protection. Two or more neos on a table will inevitably collide, and often they chip when that happens.
4.) A point to consider is that the wire, battery and magnet can get very hot. Especially so when the Heart is not turning efficiently, or is stalled out. Be careful with your fingers until you understand about this.
5.) Don't allow the Hearts to rotate very long, as the battery will get over-heated and have a short life. If the battery feels too hot to touch, it has gone too far.
Have fun and play safe out there!