Welcome to today’s episode, hosted by wilderness medicine expert Dr. Kathy Vidlock. In this episode, Dr. Vidlock walks us through a real case from the backcountry—a hiker who developed supraventricular tachycardia, or SVT, away from definitive medical care.

Dr. Vidlock explains what SVT is, why it can strike suddenly even in otherwise healthy individuals, and how the stressors of the wilderness—dehydration, exhaustion, heat, stimulants, and altitude—can increase the risk. She breaks down the signs and symptoms you might see in yourself or a companion, from rapid heart rate to anxiety, dizziness, and chest discomfort.