Strawberry plants are hardy but the flowers are not. Frosting of the flowers can show up later on as brown, unformed or deformed berries, or simply no fruit.
Like all other plants they will need to be hardened off (ie putting them outside in the day if it's not freezing or very windy, then bringing them back in at night) for a week or so before going out permanently, if they have been kept indoors. This helps the leaves to toughen up before they are exposed to the full force of outdoors - although at the moment outside is like the middle of summer here.