Really useful advice from Her Majesty’s Government
What to do in the event of a chemical or biological attack? Why, “go indoors and listen for specific instructions which will be broadcast on the radio”. We should also take “sensible precautions” such as having battery powered torches, radio, ready to eat food, bottled water and blankets close to hand. However, the government says there is no need at present to take further measures such as stockpiling food or buying a gasmask.
Phew! I feel better already.