Passed out after smoking weed?

So, last night I was just jamming with my brother and hitting the bong, something I do on a regular basis. But after I smoked a second bowl, a couple minutes later I began to feel light-headed. It just continued to get worse until I eventually straight up passed out and fell over. I was still barely conscious but very delirious as my brother tried helping me up. I then passed out again. About a minute after I first passed out, I started to regain vision and full consciousness. I've been smoking weed for years, but have never passed out. I have been recovering from a cold, but I've been smoking all throughout it. Was this just a severe green out or may have it of been some other health problem?