Yes, when you get into it and start seeing vids of those going up, well not something you want in your bag or charging at home.
I think this was on another thread (it deserves its own really !! I will post it up in a separate thread), but it may have even been on this one . . .
Very good article about lithium batteries from Airbus, particularly how to deal with a fire incident on a plane, but apples anywhere of course.
Today, Lithium batteries play a barely visible, yet essential role in both our daily life and aviation alike. Manufactured and handled correctly, Lithium batteries are safe. But production failures, mishandling, or not being aware of their specific characteristics can have serious repercussions.
safetyfirst.airbus.com
There is a pdf download of the doc on the top of that page, very good to download and read up.