According to your description, stung by a bee, the injury is not serious, you can take the following treatment:

1, first of all, the surface of the skin to see if there is a venomous stinger into the skin, if there is a stinger first plucked.

2, the choice of soapy water, 3% ammonia, 5-10% sodium bicarbonate water, saline, sugar water wash wound.

3, take some alkali (edible alkali on the line) get wet in the sting on the line, this method is simple but very useful.

4, in the field was stung by bees, if there is no alkali, you can find a kind of bush called "thorns" (the field of this plant a lot of), its leaves mashed (no tools, with a stone on the line) in the stings.

But if it's too serious, such as being stung by a large swarm of bees, it's best to go to the hospital for professional treatment.