ScienceSpark on Instagram: "Explanation:- sealing a sucking chest wound with an occlusive dressing (like plastic taped on three sides) creates a flutter valve, allowing air out but not in. This is a standard first aid method to prevent tension pneumothorax, per sources like Merck Manuals and Verywell Health. Seek professional medical help immediately after. Taping on three sides creates a one-way valve: air escapes during exhalation but can't enter during inhalation, preventing tension pneumotho