Not with apples but with peaches and plums. Luckily fruit trees produce way more blooms than they can grow fruit. Not all of the blooms, in all likely hood, have bloomed, and a light frost will do nothing except thin the fruit for you. It all depends on how long it is below 32F. If only for a short period you probably won't know the difference. Blooms can withstand temps below freezing down to about 25F-27F for short periods. What is really affected by 32F temps are the tiny fruit that have just set and 32F will kill them.
When I get a frost or a light freeze I get out my water hose and spray everything down with water at dawn. It keeps the plant tissue from bursting from the frost damage. It works very will with tomatoes too, but the trick is to get the water on the plants before the Sun hits the plants in the morning. When the sun hits the plants in the morning the frozen plant cell will burst due to the drastic temperature change from the Sun. Water works very well to prevent frost or a light freeze on almost any plants outdoors.
And another trick is to not spray too much water. I actually did spray too much water one time and it is why I don't recommend it. I actually split a gorgeous peach tree right down the middle of the trunk. The weight of the ice was too much and one complete side of the tree split for a distance of about 3 feet. Needless to say, out came the chainsaw.