Instruction: Given a question and the related document, and generate the answer to the question based on the information provided in the document.

Input:
Question: Does it shut off automatically?
Document: This Vicks Nursery Vaporizer is easy to use, and it is safe because it is automatically shut down the heat when there is not enough water. But you have to add a little salt to generate vapor, and you need to control the amount of salt because if you add too much, it will vaperize too quickly and the boiled water will generate noise. The inside black heater often makes the water quite dirty.
I've used this vaporizer for years, and after trying the "Vicks Warm Mist with Auto Shut off", I am going back to this one.This is a no-frills vaporizer like I remember from my childhood, a long time ago. It has not changed very much but I think it's still the best design.Pros:-Priced cheap. Even if it only lasts a year, you will get your money's worth.
we love this it works great bacteria free had it for 3 years use it every winter for our son
very good product, it really works. had helped my doughter during her crisis of asthma.... I use it some times too.
product has helped me breath better since I moved it right smack dab next to my bed. good for a small space... good safety switch.
it doesn't produce vapor very well and a day after the return window it stopped altogether. Not to mention it leaves black chunks in the water. Piece of garbage. More valuable as a bed pan.
Yes it's cheap. Yes it does mist up the room very well. However, after 2-3 hours, the water is filled with soot and the mist starts to smell like soot. It's hard to explain. I think it's a piece of junk and will have to buy yet another humidifier. I also think it's not safe because the top does not latch on. Really bad product.
Works fine though with small capacity; runs for 8-9 hours. Compact for easy storage and a good value (I paid $11.96) for a basic vaporizer. When you first insert the heating element it tends to float up but then settles into place as the water seeps in. (It lacks a  lock or screw tight mechanism.) We have used this overnight in our bedroom when fighting  a cold.
While it is very easy to clean, lightweight/easy to carry, and very affordable, I would simply recommend purchasing one that is more powerful, because otherwise, you will really need to place this thing on the floor next to where your head is when you sleep so that what little bit of steam it puts out can rise to where you or your child is sleeping. Don't buy unless it is all you can afford. Or just try the napping in the bathroom thing to clear out those sinuses.
We've tried many vaporizers, but this one works wonderfully in many ways.Water tends not to get as many particles after a full days use as smaller units for some reasonNight light nice but not too bright.Unit fits perfectly in bathroom sink to be refilled.Mine operates for about 15 or 16 hours before it needs to be refilled!
Answer: Yes, it has.