A rheostat is a device which is used to vary the resistance in an electrical circuit without interrupting the circuit.heostats are a kind of potentiometer. These devices can be used in a variety of settings, and are usually designed to be sealed so that environmental factors cannot interfere with the function of the circuit.
This chemical can cause allergic rhinitis and its symptoms, including a runny nose, sneezing, and itchy eyes. In addition to tree pollen, other common allergens include: grass pollen
1 It also is called seasonal allergic rhinitis because symptoms are triggered by an allergic reaction. 2  People with hay fever experience symptoms during certain seasons. 3  It is common in the spring, summer, and fall. Symptoms include runny nose, congestion, sneezing, watery eyes, itchy eyes, itchy throat, cough, and difficulty breathing. 2  Hay fever is not contagious. 3  The best treatment is prevention. 4  Over-the-counter medications or prescription medications may help ease symptoms.