Now, there are electromagnetic changes [during projections] that can be perceived with instruments. Certain electrical fields will make themselves known under these conditions. The fields have always existed, but they will become apparent to physical instruments only when they are being crossed — in other words, at the very act of projection. Other hints: A cool body temperature but with room temperature between 73.8 and 75.9. High humidity is poor. The color of a room is important. Cool colors are best. Too warm colors are detrimental, being too closely allied with earthly conditions.

p. 347 - Seth, Dreams & Projections of Consciousness, (1986)