You try being dragged under a truck while wearing breathable cotton, see where that gets you! (it's on telly over here right now!). Oh, you want heresy? Not a single thing Indy does in the film has any bearing on the outcome of the plot. If he'd stayed home and marked papers, it would have been exactly the same!
Everything Indy does is designed soley for our amusement. Plot, what plot!?