As always, read the chemical instructions carefully because many insecticides are toxic if used improperly. Finally, wait an hour and hose off the plant so you don't bring the chemical scents back in the house also. Don't forget to clean the outside of the pots also, especially the underneath of the rim because this is a favorite place for spiders to lay eggs. After bringing the plants in, let the soil dry out before watering again. This will kill off any remaining insect eggs hidden in the pots.
Many insects thrive in warm moist soil, and regular watering encourages their survival.
Many houseplants go through a climate change after being brought back in. They will react by the yellowing of leaves that eventually fall off. This is normal, especially in tropical plants like hibiscus and bouganvillia, and is not a cause for alarm. Continue to provide sunlight and water, and the new, healthier looking leaves will soon sprout. Take the time to prevent problems such as a slug that isn't discovered until December, a little red ant invasion, or gnats.