In the absence of elevated temperature, we think mainly of dehydration, anemia, hyperthyroidism (over active thyroid gland). Of course these are just a few and common entities that may precipitate tachycardia (rapid heart rate) and dyspnea (shortness of breath). A full evaluation by a physician,including a detailed history about the time of onset of symptoms, frequency,factors that make them improve or worsen, associated symptoms, occupational history, stress etc, in addition to physical examination, are required to make the right diagnosis.