Hello! Welcome and thank you for asking on HCM! I understand your concern and would explain that your symptoms may be related to dehydration (low water intake and increased sweating related to the hot weather and physical activity). A chronic anemia and other metabolic disorders (adrenal gland insufficiency, thyroid dysfunction, orthostatic intolerance) could also cause this clinical situation. I recommend consulting with your GP for a careful physical examination, a resting ECG and some blood lab tests : -complete blood count (chronic anemia) -PCR, sedimentation rate (inflammation) -fasting glucose -blood electrolytes -kidney and liver function tests -thyroid hormone levels -cortisol plasma levels. A head up tilt test is necessary to exclude possible orthostatic hypotension. Meanwhile, I recommend you to take plenty of water, avoid working in hot places and straining physical activity. Hope to have been helpful! Best wishes! Dr. Iliri