 Just like the swelling and the pain were caused by one thing, increased permeability of the capillaries, redness and heat are caused by one thing. Inflammatory cytokines cause vasodilation. Now think about that. Vasodilation, you are going from a little red capillary or blood vessel, arterial or venial that's here, and then you vasodilate. And how is it possible that that causes redness and heat? If you vasodilate, you're going to increase blood flow. Do you agree that if you increase blood flow, it's going to get red? Think about when you go running, just like this. That's what you look like, huh? You're off running, and pretty soon as you're running, what happens to your face? What happens to my face is that my face gets red. Why? Because I vasodilate like everything in my face. And I vasodilate because I'm burning so much energy because I'm such a rock star that I'm getting super hot inside my core. And my blood is like, dude, we got to cool off. So we vasodilate in my face, and it turns bright red so that my blood can cool itself on the surface of my skin. Vasodilation causes redness. Totally cool. If you are putting more blood in a place, what are you going to feel? What happens to your face when you vasodilated it so you can go for your run? It gets hot, holy hot face because you vasodilated your face. It gets down, which makes complete sense. So yes, vasodilation causes redness and heat. Now, the question is why? What is the advantage? Why would this be a beneficial thing to increase blood flow to an area? How about our warriors, our white blood cell warrior dog pounds? Bring them in. If we increase blood flow to a site of damage, we are going to bring in more white blood cells who can attack. You know what? We're going to bring in more blood, period. Remember that our blood contains all our plasma proteins, including antibodies. If you shut down blood supply to an area of damage, and this is, this, you should think about this because when you damage a vessel, if you break the vessel, then you're going to go through the whole clotting thing. You're actually going to have vasoconstriction happen if you break your vessel. But if you have an inflammatory response and all you're doing is creating chemicals, you haven't, you've actually increased the permeability of your capillaries. The increased permeability and the vasodilation are going to allow more blood flow to that area. If that blood vessel was broken, vasodilation would be a bad idea. It's not a broken blood vessel. We're just going to bring in the opportunity to have more warriors come to the fight. Does that make sense for your cute little brains? I hope so. Now, one of the things that happens, one of the things that's found in the blood that can possibly be a tool for battle is something called complement. And it doesn't mean that you said, oh, you look very lovely today. Not that kind of complement.