Common Cold: A catarrhal disorder of the upper respiratory tract, which may be viral or a mixed infection. It generally involves a runny nose, nasal congestion, and sneezing.Echinacea: A genus of perennial herbs used topically and internally. It contains echinacoside, GLYCOSIDES; INULIN; isobutyl amides, resin, and SESQUITERPENES.Rhinovirus: A genus of PICORNAVIRIDAE inhabiting primarily the respiratory tract of mammalian hosts. It includes over 100 human serotypes associated with the COMMON COLD.Cold Temperature: An absence of warmth or heat or a temperature notably below an accustomed norm.Nasal Decongestants: Drugs designed to treat inflammation of the nasal passages, generally the result of an infection (more often than not the common cold) or an allergy related condition, e.g., hay fever. The inflammation involves swelling of the mucous membrane that lines the nasal passages and results in inordinate mucus production. The primary class of nasal decongestants are vasoconstrictor agents. (From PharmAssist, The Family Guide to Health and Medicine, 1993)Nasal Lavage Fluid: Fluid obtained by THERAPEUTIC IRRIGATION or washout of the nasal cavity and NASAL MUCOSA. The resulting fluid is used in cytologic and immunologic assays of the nasal mucosa such as with the NASAL PROVOCATION TEST in the diagnosis of nasal hypersensitivity.Nasal Sprays: Pharmacologic agents delivered into the nostrils in the form of a mist or spray.Picornaviridae Infections: Virus diseases caused by the PICORNAVIRIDAE.Multi-Ingredient Cold, Flu, and Allergy Medications: A broad category of multi-ingredient preparations that are marketed for the relief of upper respiratory symptoms resulting from the COMMON COLD; ALLERGIES; or HUMAN INFLUENZA. While the majority of these medications are available as OVER-THE-COUNTER DRUGS some of them contain ingredients that require them to be sold as PRESCRIPTION DRUGS or as BEHIND-THE COUNTER DRUGS.Antitussive Agents: Agents that suppress cough. They act centrally on the medullary cough center. EXPECTORANTS, also used in the treatment of cough, act locally.Nasopharyngitis: Inflammation of the NASOPHARYNX, usually including its mucosa, related lymphoid structure, and glands.Coronavirus 229E, Human: A species in the genus CORONAVIRUS causing the common cold and possibly nervous system infections in humans. It lacks hemagglutinin-esterase.GluconatesSneezing: The sudden, forceful, involuntary expulsion of air from the NOSE and MOUTH caused by irritation to the MUCOUS MEMBRANES of the upper RESPIRATORY TRACT.Nasal Lavage: Irrigation of the nose with saline or irrigation solutions for diagnostic or therapeutic purposes. It is used to remove irritants, allergens, or microorganisms from the nose.Expectorants: Agents that increase mucous excretion. Mucolytic agents, that is drugs that liquefy mucous secretions, are also included here.Respiratory Tract Infections: Invasion of the host RESPIRATORY SYSTEM by microorganisms, usually leading to pathological processes or diseases.Phytotherapy: Use of plants or herbs to treat diseases or to alleviate pain.Nonprescription Drugs: Medicines that can be sold legally without a DRUG PRESCRIPTION.Zinc Acetate: A salt produced by the reaction of zinc oxide with acetic acid and used as an astringent, styptic, and emetic.Virus Uncoating: Intracellular step that follows VIRUS INTERNALIZATION during which the viral nucleic acid and CAPSID are separated.Coronavirus Infections: Virus diseases caused by the CORONAVIRUS genus. Some specifics include transmissible enteritis of turkeys (ENTERITIS, TRANSMISSIBLE, OF TURKEYS); FELINE INFECTIOUS PERITONITIS; and transmissible gastroenteritis of swine (GASTROENTERITIS, TRANSMISSIBLE, OF SWINE).Coronaviridae Infections: Virus diseases caused by CORONAVIRIDAE.Histamine H1 Antagonists: Drugs that selectively bind to but do not activate histamine H1 receptors, thereby blocking the actions of endogenous histamine. Included here are the classical antihistaminics that antagonize or prevent the action of histamine mainly in immediate hypersensitivity. They act in the bronchi, capillaries, and some other smooth muscles, and are used to prevent or allay motion sickness, seasonal rhinitis, and allergic dermatitis and to induce somnolence. The effects of blocking central nervous system H1 receptors are not as well understood.Nasal Mucosa: The mucous lining of the NASAL CAVITY, including lining of the nostril (vestibule) and the OLFACTORY MUCOSA. Nasal mucosa consists of ciliated cells, GOBLET CELLS, brush cells, small granule cells, basal cells (STEM CELLS) and glands containing both mucous and serous cells.Humidity: A measure of the amount of WATER VAPOR in the air.Coronavirus: A genus of the family CORONAVIRIDAE which causes respiratory or gastrointestinal disease in a variety of vertebrates.Coronavirus OC43, Human: A species in the genus CORONAVIRUS causing the common cold and possibly nervous system infections in humans. It contains hemagglutinin-esterase.Sulfinic Acids: Any of the monobasic inorganic or organic acids of sulfur with the general formula RSO(OH). (From McGraw Hill Dictionary of Scientific and Technical Terms, 4th ed)Zinc Compounds: Inorganic compounds that contain zinc as an integral part of the molecule.Plant Preparations: Material prepared from plants.Carrageenan: A water-soluble extractive mixture of sulfated polysaccharides from RED ALGAE. Chief sources are the Irish moss CHONDRUS CRISPUS (Carrageen), and Gigartina stellata. It is used as a stabilizer, for suspending COCOA in chocolate manufacture, and to clarify BEVERAGES.Mucus: The viscous secretion of mucous membranes. It contains mucin, white blood cells, water, inorganic salts, and exfoliated cells.Ascorbic Acid: A six carbon compound related to glucose. It is found naturally in citrus fruits and many vegetables. Ascorbic acid is an essential nutrient in human diets, and necessary to maintain connective tissue and bone. Its biologically active form, vitamin C, functions as a reducing agent and coenzyme in several metabolic pathways. Vitamin C is considered an antioxidant.Pharyngitis: Inflammation of the throat (PHARYNX).