You see kids playing on frozen lake, what would you do? let their parents know it's a little dangerous, talk to kids, ignore them or drink water?

Drink water. Water is healthy

It depends on if it's a safe situationor not. If it's not a safe situation or if a child is misbehaving I have no problem telling other people's children what to do and have on many occasions.

Before I answer, are really hot heat lamps available in this scenario?