How about those after dinner mints? They are made in pastel colors, but they won't melt. You can find them in the Bridal dept. of most stores.

Jelly beans would be really cute. M&Ms especially if you get them customized at mymms.com is really awesome with a great variety of colors. My friend gave out M&Ms at her summer wedding in southern california and it didn't melt =)

JELLY BEANS

you can get them fairly inexpensive after Easter, saved us a ton.

candy canes? joke. plain candy. Actually, chocolate would work, just give it to them after you put them to the fridge

Jelly Beans...If you have patience you can sit and pick out your wedding colors