4. Cold Weather.
Many people can’t stand winter, but a select few shouldn’t stand it at all. People with cold urticaria come down with hives, redness, itching and swelling after exposure to cold temperatures. In the worst case scenario, very often when a person with the allergy swims in very cold water, it can even lead to shock, fainting, brain damage and death. Like many rare allergies, it’s likely that this one is under-diagnosed.