Chestnuts, but where's the Open Fire?

I took a walk in the park near my office today and found the ground absolutely covered in chestnuts, which are ripe and falling off the trees everywhere.

And yet I haven't seen guys selling roasted chestnuts over an open fire on the street, as you do at this time of year in Portugal, Spain and New York, among other places.

It's not that the French don't eat chestnuts -- they're an important part of the national cuisine at this time of year.

A coworker suggested that while chestnuts may be in season, open fires aren't, yet -- it's Indian summer here and about 80 degrees outside.

Still, it's puzzling.