Bedrooms were especially worrisome, as people spent so long in them. Dr Pye Henry Chevasse, a physician who wrote health manuals for the layperson in the Victorian era, was willing to go so far as to state that it was ‘madness to sleep in a room without ventilation – it is inhaling poison; for the carbonic acid gas, the refuse of perspiration, which the lungs are constantly throwing off, is … deadly’.
