 If you're moody, blame the heat. CBS's Donya Backus with Cleveland Clinic psychologist Dr. Susan Albers. I just feel like I get tired more. Research shows excessive heat can impact mood, triggering increases in anxiety, stress, and cognitive difficulties. Cleveland Clinic psychologist Dr. Susan Albers says when the body has to work harder to keep cool, that causes the release of the stress hormone cortisol. During the heat waves, people tend to feel more agitated. Everyone's mood is impacted by the heat.