*Cold weather/snow: Exposure to<unk>  or cool air can quickly trigger a reaction; for example going down the "cold" aisle in a supermarket. * Sweat: A reaction may even occur on a warm day when there is sweat on the skin, since the reaction is triggered by skin temperature, not core temperature. If there is a breeze it will rapidly cool the skin and create hives. *<unk> /cool IV lines: While in the hospital, inserting IV lines that have been refrigerated or are cool into individuals who are allergic to<unk>  temperature can/may result in pain within the limb the IV is placed and a line of hives may appear within a radius of 6-8 inches from the IV site in the pattern of a line going up the limb. * Swimming: Swimming can be especially dangerous as the rapid heart rate combined with the onset of hives can lead to hypotension. * Air conditioning: Entering a cool building during a summer day can result in an allergic reaction to exposed areas of skin, congestion from breathing the cool air and possibly feeling fatigued. *<unk>  foods/drinks: Eating or drinking<unk>  or cool substances such as ice cream or even iced tea may result in the individuals tongue and surrounding tissues swelling and to suffocation. * Cool/cold surfaces: Sitting on sidewalks which are cool, leaning on or grabbing a<unk>  pole will result in hives forming on the area which had contact with the cool surfaces. * Restriction of blood flow: Typing or other activities which tense muscles and reduce blood flow can cool the body parts enough to cause itching and hives. * Blood flow: While putting hands or feet in hot water nails turn purple/white until the body gets used to the temperature.
Cold urticaria
Heat urticaria
Solar urticaria
Pressure urticaria
Aquagenic urticaria
Physical urticaria
Cholinergic urticaria
Delayed pressure urticaria