In emergency medicine, quick thinking can mean the difference between life and death. For EMS professionals, recognizing and treating reversible causes of cardiac arrest is critical. This is where the "Hs and Ts" come in. These are the most common and treatable causes of cardiac arrest, and knowing how to manage them can save lives. In the field, EMS teams must act fast. Every second counts, and that’s why understanding how EMS professionals handle Hs and Ts on the field is essential to improving outcomes. What Are the Hs and Ts? The Hs and Ts refer to a mnemonic used to remember the common reversible causes of cardiac arrest. There are five Hs and five Ts: Hs: Hypovolemia Hypoxia Hydrogen ion (acidosis) Hypo-/hyperkalemia Hypothermia Ts: Tension pneumothorax Tamponade (cardiac) Toxins Thrombosis (pulmonary) Thrombosis (coronary) These causes are central to Advanced Cardiac Life Support (ACLS) protocols and are routinely assessed during a code. How EMS Handles Hs and Ts in...