Cholinergic urticaria (heat hives) is a terrible condition in which the body will break out into a tingly, painful, but intensely itchy feeling when the person becomes hot, exercises, gets stressed out, nervous, or if the body temperature rises.ther symptoms of heat hives may include: 1  Red flushing during the breakout (like how your cheeks blush when you get embarrassed) on areas of the body. 2  Small hives or bumps (ranging from the size of tiny mole to the size the pupil of your eye) that may appear on the body.
Medical conditions such as thyroid disease, low blood sugar, anemia, and low blood pressure also may cause palpitations. Heart palpitations may be a sign or symptom of arrhythmia, an irregular heartbeat, or other heart conditions such as heart attack, heart failure, heart valve disease, or cardiomyopathy. Although palpitations are very common and usually harmless, they can be frightening when they happen and may cause anxiety.
Common causes of heart palpitations include: 1  Strong emotional responses, such as stress or anxiety. 2  Strenuous exercise. 3  Caffeine. Nicotine. 4  Fever. Hormone changes associated with menstruation, pregnancy or menopause.  Taking cold and cough medications that contain pseudoephedrine, a stimulant.