Climate change and global warming present major clinical challenges. We focus on cardiovascular and renal clinical consequences. The physiological adaptations and physiopathological effects are described, especially in vulnerable populations. The clinical consequences during heat waves, are mainly cardiovascular with stroke, acute ischemic heart disease and sudden death increased by up to 40%. Likewise, episodes of acute renal failure, electrolyte disturbances and kidney stones disease increase. The chronic consequences should not be overlooked, as the risk of heart failure also increases in high ambient temperature regions and there is also some evidence of an increase in chronic kidney disease in tropical zones. Physicians must be aware of these consequences as they will be involved in their management in the future.