How should a parent handle it when their child has a temper tantrum?

Temper tantrums are thoroughly normal anytime after your child turns one year. They generally peak between 18 mos and 2-1/2 yrs, and then gradually fade away as your child learns more mature ways to express wants and frustrations.  Toddlers are learning skills so fast that they get a bit intoxicated with how powerful they are, or think they ought to be, and will try to control their parents just as they are trying to exert an effect on the rest of their world. 

The tantrum is usually brought on by someone saying "no", so the first response is to choose your battles. Say yes when you can, and you will be setting a good example of how to be an agreeable, responsive human being.   Try to give your child choices, or other options, and try to say, "No, you can't have the glass vase, but let's go play with your blocks together ( and then hide the glass vase!).  This is called "redirecting", or just distracting your toddler, and works for awhile but then they catch on.  That's when it's important to have said "No" only when you mean to stick to it. 

Make sure your child isn't acting up simply because she isn't getting enough attention. To a child, negative attention (a parent's response to a tantrum) is better than no attention at all. Try to catch your child being good, which means rewarding her with attention and lots of praise for positive behavior.

It's important to set strict limits regarding safety, aggressive or dangerous behavior.  If a tantrum ensues, at that point, you can acknowledge your child's feelings ("I know you're mad"), but reiterate the limit you've set ("but hitting is not allowed in our house").   Then, turn away, and IGNORE that tantrum.  If your child bangs his head or throws up, he's raising the ante, but you need to REMAIN CALM, put him in a safe crib or playpen or childproof room, or just hold him without talking about the behavior.  This is no time for a discussion or negotiation, as those words won't be heard at all.   If a tantrum is escalated, and then you finally give in, you are teaching your child that tantrums work, a very bad lesson.

Keep in mind that tantrums are MUCH more frequent when your child is hungry, tired or bored, so keeping up routines and being consistent is very important, especially around meals, naptimes and bedtimes, and activities.  Remaining calm can be really, really hard sometimes - don't let that mood be contagious!  Try mentally channeling your most admired calm supportive role model (preschool teacher, star babysitter, firm unflappable grandparent, etc).

A fun and helpful book is The Happiest Toddler on the Block, by Harvey Karp, M.D.