The first time my daughter had a tantrum, I called her pediatrician. I know that sounds crazy, even more so because she was my second child, and I was already a seasoned tantrum handler. But my daughter was only 13 months old, and she kicked, screamed and rolled around on the floor for an entire hour. She was inconsolable and she did not stop until she was thoroughly exhausted. Her tantrums peeked around 3 years old, to the point that I was often afraid to leave the house with her, not knowing when she would completely loose it.
The ultimate tantrum occurred at this time, in a restaurant,(luckily towards the end of the meal). She somehow lost a very tiny piece to a toy she had just bought with grandma (I advise against ever purchasing any thing so small that you have to crawl around on the floor to even see it) and we searched for it, but couldn’t find it. She began to cry, then scream. I quickly put the baby in her seat, and had grandma and grandpa take my other two children to the car as I pried my now screaming three year-old, who was refusing to leave with out the bone from her Polly Pocket set. She was gripping the side of her chair so tight that I had to pry her little fingers one by one to release them (in front of a full audience of diners) And carry her through the crowded restaurant.
It didn’t stop there. She refused to be buckled in the car, and when I leaned over to secure her belt, she lifted her knees to her chest, got her feet under me and kicked straight out, pinning me to the back of the drivers seat. I had kept my cool until then, and at this point I didn’t even scream, I cried in pain. I won’t finish this story. I will only say that it took me 3 months to get the courage to enter another restaurant with her.

Now, at four years old, she still has the occasional tantrum, but when she is put in her room to get over it, she will then tell me that she cried because I didn’t give her what she wanted. It has been a long road, getting her out of this cycle, helping her learn to use her words to express herself instead of screaming, and deep down, I still have a fear that she may go crazy on me again. I took four months for me to venture out with her to another restaurant after that incident, and she was a perfect angel.
Toddler Tantrum Taming is an extensive article I wrote at HubPages that includes tips and advice on preventing and managing tantrums.