Seek immediate medical attention if the individual is wheezing, not getting enough oxygen or has signs of cyanosis: bluish lips and nail beds, pale colour. While you wait for medical attention:

FOLLOW THE DOCTOR’S INSTRUCTIONS.
Administer any medication that was prescribed by the individual’s doctor.

HAVE THEM SIT UP STRAIGHT IN A CHAIR.
Ask them to lean forward and rest their forearms on a table, elbows pointing away from the body.
OFFER A BEVERAGE.
Coffee, black tea or a hot liquid like clear tea can help dilate the airway. If available, lobelia tea (1⁄4 tsp of herbs or 5 to 10 drops of tincture to 1 cup warm water) may help.

APPLY A COLD-WATER COMPRESS TO THE CHEST.
In some cases, it may stop the attack.

Adapted from The Natural First Aid Handbook by Brigitte Mars (Storey Publishing).