LaserPointer stopped working, burning hot, what happened?

Hi all, I'm basically a rookie so bear with me if you would.

I'm a high school physics teacher. Last school year I bought a cheap green laser online and used it for teaching waves & optics. Worked fantastic. I put it away, and just pulled it back out today to use this year, here's what I did and experience:

1. Laser wouldn't work, so I replaced the batteries (regular AAA batteries).
2. Laser wouldn't work with replaced batteries, and I thought I might have them in the wrong direction so I flipped them around.
3. Laser still didn't work, so I set it down and started googling on the internet for possible simple fixes.
4. A few minutes later I put my hand on the laser pointer to pick it up, and it is burning hot. (I manage to get the think unscrewed and the batteries out with a determined quick motion, so obviously it could have been even hotter.)

It took several minutes for the laser pointer itself to cool down, and even longer for the batteries.

Can you tell me what happened?
Can you give me advice so as to make sure I maintain my laser pointer properly?

Best,
mathayus

Sounds like the driver shorted on the metal case of the laser, the laser is probably fried. You can get them on ebay for 5$.

You can also buy something like this, it may be better for demo's because it's got a longer duty cycle and mains powered. 532nm 50mW TTL Power Adj Laser Tec Fan Cooling with 90 240VAC | eBay