On committing to the Tunnel turn-off, I discovered that the traffic was grid-locked. So I had to work my way through 3 congested lanes of virtually stationary traffic inside the tunnel. At the entrance to the Tunnel, the bike's air temperature gauge started at 32 degC and rose to over 46 degC by the exit. A truck had broken down on the road at the river end.
Those exhaust fans in the tunnel are pretty close to the loudest things I have ever heard, and very disconcerting in the narrow confines of the Tunnel.
Honestly soaked through with perspiration and mild heat exhaustion from the experience.
Stationary in traffic in the Tunnel, no airflow, no room, vehicle engines and air-conditioners pumping out heat, never want to repeat that again...