What mnemonic helps firefighters remember a set of lighter-than-air gases?

The mnemonic "4H MEDIC ANNA" is designed to help firefighters and emergency responders easily recall a specific list of lighter-than-air gases. This technique is particularly useful in hazardous materials situations where quick identification of gas types is critical for safety and response. The mnemonic typically includes the names of gases such as Hydrogen, Helium, and others, helping responders to remember which gases they might encounter that will be less dense than air and therefore rise.

By utilizing such a mnemonic, firefighters enhance their ability to quickly assess risks associated with different gas types, which is essential during an emergency response. Effective memory aids like this can significantly improve a team's operational efficiency and safety on the scene.