steep steps to flat
shut out the bitter world -
a heart pounds
Please see the poem, SUMMER DIRECTLY TO WINTER - 2010, for details and explanation re this haiku.
Regarding the words used: They are in common use by British (here and and in the UK). EG:
"What is it like out?" (not: "outside")
"It is bitter!" (exceptionally cold)
"Where are you going?"
"Going to flat."