Although a bee sting can be painful, it is usually fairly harmless.
Because a bee's stinger will continue to pump venom into the skin, the first thing you want to do is remove the stinger. There will be a small black dot in the center of the area that is red. You should try to scrape the dot off with your fingernail. Never squeeze the stinger with your fingers or tweezers. Doing so may release more venom.

After removing stinger, clean the skin with soap and water. An ice pack held on the area for about 15 minutes will ease the pain and minimize the swelling. Make sure that the ice pack is covered in a cloth so it does not burn your toddler’s skin.

You can also use a mixture of baking soda and water, stirred into a paste. Rub the paste onto the bite and let it dry. The baking soda will help draw out the venom and soothe the skin.

The pain from a bee sting will begin to subside quickly and will normally be gone in a couple of hours. If your toddler is in pain, you can give them paracetamol or ibuprofen and apply icepacks. If the swelling warrants it, use an over-the-counter children's antihistamine. This will also keep your child from scratching the area.