A deployable heat and smoke obstacle is disclosed. A screen is wound around a shaft over a passageway in a building or a vehicle. The shaft can rotate in response to an alarm signal to deploy the screen over the passageway to prevent smoke and heat from passing through the passageway. The screen includes magnetic sheets that engage a corresponding magnetic surface near the passageway to hold the screen in place over the passageway. The screen also includes heat-sensitive fasteners that deform when heated to engage corresponding holes in the passageway to hold the screen in place over the passageway.