Aromatherapy is a widely used term for a range of traditional therapies that use essential oils and other plant compounds for healing. For physiological conditions, specific essential oils are used for their effect on various muscles, organs and their function as well as the oils' influence on hormones and the immune system in order to bring about a therapeutic result. Stress, anxiety and other psychological conditions can be managed effectively by inducing relaxation, changing moods and soothing the emotional mind and body by acting directly on the nervous system. Aromatherapy is used by spiritual and energy healers working on the subtle body, in meditation and prayer for the vibrational effect of the essential oils. Certain aromas activate our sense of smell and influence our mood and emotions; they can remind us of events and help us to remember places, things, and people. Aromas can make our environment smell inviting, whether that be refreshing on a hot summer day with a citrus scent or cosy and warm with cloves, orange and berries, all to directly improve the air quality of our indoor environment. Some essential oils can clean and purify the air we breathe and even kill airbourne bacteria.