Which of the following is not part of the five Hs?

• A. Hypoxia
• B. Hyperthermia
• C. Hydrogen Ion Imbalance
• D. Hypothermia

Answer: (B)

The five Hs are a quick checklist of reversible problems that can cause or worsen cardiac arrest: hypovolemia, hypoxia, hydrogen ion imbalance (acidosis), electrolyte disturbances, and hypothermia. Hyperthermia isn’t included in this mnemonic, so it isn’t considered one of the five Hs. Among the options, hypoxia, hydrogen ion imbalance, and hypothermia are all classic Hs, while hyperthermia is not.