I'd keep it cold in a thermos container. It should still be very tasty. If it's hot, it could get rubbery.

And another useless factoid. Although it's a cliche of Italian-american cooking "shrimp scampi" is redudant. It means loosely translated, "shrimp style shrimps."

Personally I'm not a big fan of reheating shellfish. And holding it unrefrigerated is a seriously bad idea.

I tend not to send shrimp leftovers in the lunchbag because of the strong smell that can linger. If they spill or the thermos isn't completely sealed after they eat, the bag will smell forever.

I don't worry about the safety of the food--if it's a party, the food sits out a longer amount of time than the time leaving for school to lunch. I wouldn't want them smelling of garlic and maybe getting dumped on bec. of that.

I pack hot leftovers for my daughter all the time in a thermos container to keep them hot. Re-heat in the morning when I pack her lunch and then put it in one of these:
http://www.thermos.com/product_details.aspx?ProdID=1190&CatCode=LUNC

Works great for pasta, stews, even soups.

They're even recommended by Good Housekeeping:
http://www.goodhousekeeping.com/product-testing/reviews-tests/childrens-toys/best-thermos-containers

Much better than sending them with stuff in tupperware to gradually rise in temperature through the day and end up as a lukewarm ghost of what it might have been...

augenblick, if i was one of your kids, i would want it too! having awesome left-overs from food is an excellent way to earn street cred on the playground and will send other kids home to their parents wondering why they didn't get shrimp scampi as well. the two things to consider are A) tupperware - not all children are great and keeping track of your prized food containers and may lose them...so you mind want to use recyclable gladware if your child is the forgetful type and B) the temperature danger zone. most grade school and secondary school students don't have access to refrigeration while at school and so their food may sit in the 41-135F temperature range for more than 4 hours before they eat their lunch, which is the time length FDA would require food to be thrown away if it was served to them in the school cafeteria or in a restaurant. odds are they won't get sick (i never did), but just keep that in mind for future lunches like this. my mom used to freeze my juiceboxes/water bottles so it would keep my food cold all way...and didn't have to worry about carrying( in my case losing) a warm ice pack. hope this helps!

Probably not, unless you send it along with one of those ice pack things or something else to keep it cool until lunch time. I'm guessing there is no fridge at school.