According to a Penn State extension service chart, you'll lose 10% of your (unprotected) apple blossoms if it gets down to 28 degrees for 30 minutes, and 90% if it gets down to 25 degrees for 30 minutes. The chart says peach blossoms are one degree hardier. The amount of loss is going to depend on blossom stage and the siting of your trees.
Virginia used to be a big apple-growing state, and I remember years with news stories showing us how the orchards were trying to protect their crops when we'd get a late freeze. They did two main things: put smudge pots in the orchards (55-gallon drums with something burning in them), and spray the trees with water to coat them with ice. Would either of those methods be possible on your property? Obviously fire is dangerous, so I'm not recommending that one unless you make a habit of burning things and know what you're doing.
If the trees are small, you can cover them with blankets or tarps (non-plastic), preferably on a frame that keeps the material off the blossoms. If possible, you can put holiday lights or regular light bulbs in the trees to add some warmth, but they have to be incandescent or halogen, not LED. I'm guessing this is only feasible if the trees are fairly small.
Another option is to fill large containers with heated water (or let the sun heat the water) and put them under the trees. Apparently it's also helpful to water the trees (meaning, the ground around them) before the freeze, because that will help warmth radiate from the soil.
Good luck; I hope your blossoms make it through the cold snap and you get some fruit this year!
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