What do their poops look like?
It's hard to give advice without knowing what the problem is. But for starters I'd heat half the cage using a lamp or a heating pad, since extra warmth is usually helpful to a sick bird. You only heat half the cage so they can move to a cooler spot if they get too warm.
I'd give them some Pedialyte or Gatorade to drink too. There's a very simple recipe at
http://www.webmd.com/hw-popup/rehydrati ... ar=hw86827 if you don't have either on hand. Electrolyte solutions can be VERY helpful for weakened birds.
I'd also add a pinch of cayenne pepper to their food if possible - it has antimocrobial properties. Adding some probiotics to help restore good bacteria might help if it's a digestive issue.
