the bottom is character Heart (Post 24)
Sometime, it also means that people feel difficult to breath because the room windows are all closed and no air conditioning, no fresh air in the room.
Its small seal script is
Its clerical script is
Its current standard printing script for traditional character is
Its current standard printing script for simplified character is
The difference is from that between traditional Door 門 and simplified Door 门。
Its Pinyin is "Men1".