My amateur response:
Do you have a wooden floor?
If so, see if you can take up a plank near the fireplace.
If that solves the problem, put the board back, cut a hole in it and cover with a 'hit and miss' vent. The fire will have its draft, but won't have to chill you on the way (and you get extra underfloor ventilation as a side benefit).
Do you have a wooden floor?
If so, see if you can take up a plank near the fireplace.
If that solves the problem, put the board back, cut a hole in it and cover with a 'hit and miss' vent. The fire will have its draft, but won't have to chill you on the way (and you get extra underfloor ventilation as a side benefit).