Do you know what this dashboard light means? It is your tire pressure monitoring system (TPMS) telling you that one (or more) of your tires is dangerously under-inflated.
If you see the light, don't be scared! But you should make an immediate effort to check the pressure in all four tires manually using a tire pressure gauge, or swing by a local tire shop and ask them to check it for you. Many shops, including Firestone Tire and Auto, will perform this service for you and inflate them to their correct pressure as a courtesy.