Warzone / Movie:  D-Day landings (1944), as seen in Saving Private Ryan (1998)

Level Of Heat: Most intense on Omaha Beach, where Captain John Miller (Tom Hanaks) and his fellow Allied troops must dash across the sand under the crossfire of embedded German artillery.  That is, if you even make it out of the water.

The countryside provides space to breathe, but with snipers, machine gun posts and Panzer tanks everywhere, the temperature scarcely drops for Miller's team.

Has it cooled down since?  Normandie-tourisme.fr makes it sound like a lovely place.

"Visitors have a choice between seaside and countryside. The stunning beauty of the region's interior, with its thatched cottages, traditional farming and ever-changing landscapes, is matched by a long coastline...

...which stretches from the romantic cliffs and sandy beaches of Seine Maritime in the East, to the wild Cotentin seaboard and the World Heritage Site of Mont Saint Michel and its bay, with its huge tidal range and strong currents."