In the event your start taking direct fire a nice mechanic would be to get a 2 second adrenaline boost that could allow you move quicker for a short duration while you try to get to cover. Example: I was playing a raid on 213 Park Homes. Me and team was moving forward past the Laundry heading towards the steps. Two perps sprinting came down the steps. Although I tried to move quick as possible to the side to get behind
the car I didn't have a chance. I even lowered my weapon to try to gain a few precious milliseconds but not enough. Maybe its a bad idea but I know in real life if I was taking direct fire my adrenaline would kick in and you can bet "hustle" would be a great option. Thanks for the ear. Great game. Love it.

Your team should be covering you when you move. Adrenaline is an interesting thing, you can learn not to be affected by it as much. For example if you’ve ever been in a high stress environment (like a competative fight) you can have your adrenaline ‘dump’. Basically you get the boost in mental clarity, energy and strength however agter the dump follows a crash. Where basically feel like jelly. With experience you can avoid the dump and crash however you’ll still have some adrenaline or at the very least a higher heart rate.

The swat operators id imagine would have some adrenaline/nervous soon as they step out the truck due to being in a threatening environment. However they train hard so they dont lose their cool and crash. The only time i could see this being a feature of game play is if you were hit in the chest but it didnt cause damage due to armour blocking it. Its really a thing that varies from person to person. If you think adrenaline works the way you suggested then sadly no, if it did, alot of people wounded in combat would get themselves to safety rather than be on the ground in agony waiting to be rescued.