First aid sprays greatly replenish your health.
If you use one while you are near a teammate, you will both be healed.

* You can normally only carry one spray, but medics can gain abilities which will allow them to carry more than one.

First aid sprays can be found in the environment and occasionally dropped by fallen enemies. Make sure to use them wisely.

Green Herbs can be picked up to minorly heal yourself.
You can find them in the environment or off fallen enemies.

Antiviral sprays can be used to treat infection.
If you use one while you are near a teammate, you will both be treated.
However, this spray will not work on a player who has become a zombie and will actually damage them.

* You can normally only carry one spray, but field scientists can gain abilities which will allow them to carry more than one.

You can find them in the environment or from fallen enemies.