I have tried several different natural coals and I seem to get the headaches with each one, even letting them fully ash over. Personally I am going back to QL's, probably the CH QL.
Originally Posted by Genie
I get a headache from it too, and I use herbal shisha. My coals are all natural and I use as little of them as I can. For me, I think it's just from the carbon monoxide of smoking a material that is burning. Maybe you should just try taking a few more breaths in between sucking on the hose.