Because candles are frequently used in jack-o’-lanterns, flammability must be a top concern for parents when choosing costumes for their children. According to Good Housekeeping, costumes with spray-on glitter (even those that claim to be flame retardant) are the greatest risk, because the glue that holds the sparkles on can be extremely flammable. A better choice: sewed-on sequins. All costumes should be made of synthetic fabric, never cotton; generally, nylons and polyesters melt when they come in contact with a flame, but cotton can ignite quickly and the flame can travel. Capes may be a danger, too; if they’re too long, they may sweep into pumpkin candles.