Yikes! Thanks for catching this, Chris!

Ventilation by fan is ideal.

Ventilation by refrigerated air conditioning is contraindicated.

Modern air conditioning is a major cause of atherosclerosis and arteriosclerosis.

AC disrupts circadian temperature rhythms, especially for indoor people who can’t compensate with an intact circadian light/color rhythm.

Outdoor people can overcome temperature rhythms with light and color.

Indoor people — air-conditioned or not — tend to flatten or lose their circadian rhythms.

“The exclusion of the chemical rays must be absolute. The thickness of the red material employed to filter the light depends upon its nature. If paper or thin cotton material is used, four or five layers will perhaps be sufficient. If rather thick flannel is employed, two or three layers will suffice. It is more convenient to employ red glass, but in that case the glass must be very dark. To put it in another way, small-pox patients must be protected from the chemical rays with as much care as the photographer uses for his plates and paper. For artificial light neither electric light nor any too brilliant illuminant must be used. The globes and lamp-glasses should be of a very dark red. A candle is permissible on account of its feeble illuminating power. It may be used to examine the patient and give light while he is having his meals.”

According to the same source …

“The treatment should be continued without the least interruption until the vesicles have completely dried up. Even a short exposure to daylight may produce suppuration, with its sequels. It is therefore absolutely necessary to nail up the curtains, to prevent the patients and nurses from allowing the light to penetrate, for it has been found that these people, tired of being in the semi-darkness, let in the light, and so reduce to nought the good results hoped for from the treatment.”