Under siege by the Spanish flu epidemic of 1918, nurses in Lawrence, Massachusetts, treat patients in an outdoor hospital. Canvas tents kept the sick separated and less likely to spread the deadly virus. And with the success of fresh-air therapy on tuberculosis outbreaks, public health officials strongly recommended taking them outside.

Under siege by the Spanish flu epidemic of 1918, nurses in Lawrence, Massachusetts, treat patients in an outdoor hospital. Canvas tents kept the sick separated and less likely to spread the deadly virus. And with the success of fresh-air therapy on tuberculosis outbreaks, public health officials strongly recommended taking them outside.