It is really important to check out your horse before you put your rump on him. Your life depends on it.
True Life Example: A couple of years ago a group of women headed out to a park for a day of riding. The horses in the trailer were a bit keyed up. Two people took their horses out. Those horses, too, were keyed up. One woman was apprehensive about getting on her horse, so the second woman, an incredibly experienced horse rider said that she would ride him out for her. So the second woman got on this horse she didn't know, who was already keyed up, and the other horses still in the trailer are still keyed up. This was a recipe for disaster. And a disaster did occur. The second woman, an incredibly experienced rider as I stated before, got killed.
You have no business riding in circumstances as described above. The negative energy of horses travels like wildfire and can ignite your darling. This is not the time to decide you can just ride him out to settle him down. Are you kidding? Don't do it. Do some ground work with him until he settles down. You can see that when he lowers his head, licks and chews, blinks, focuses on you, cocks his leg, etc. Even a helmet won't save your ass in such situations.
Mary Dixon Adventure Horse Riding in NYS www.RideNYS.com