This depends on the type of treatments you are using. Some flea treatments are safe to touch, while some are not. So, you should check the warnings on the medicine before you handle it. If the medicine is not safe to touch with bare hands, use gloves and dispose of them carefully afterwards. And after applying for the medicine, be careful not to allow the children to pet or play with the animals. Allow some time before you touch your pets again so that there is enough time for the medication to dry and get absorbed by the skin.