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.
Specific types of palpitations may be due to structural abnormalities in the heart. Narrowing of the coronary arteries that causes a decreased blood supply to the heart muscle can cause irritability and abnormal heart beats like premature ventricular contractions, ventricular tachycardia, or ventricular fibrillation.
Palpitationsâsensations of a rapid or irregular heartbeatâare most often caused by cardiac arrhythmias or anxiety. Most patients with arrhythmias do not complain of palpitations. However, any arrhythmia, including sinus tachycardia, atrial fibrillation, premature ventricular contractions, or ventricular tachycardia, can cause palpitations. Palpitations should be considered as potentially more serious if they are associated with dizziness, near-syncope, or syncope.