Prof Hamblin (of Harvard) said in the video interview with the guy from selfhacked that sun at greater heights (multiple kilometers above sea level) does indee

Prof Hamblin (of Harvard) said in the video interview with the guy from selfhacked that sun at greater heights (multiple kilometers above sea level) does indeed give some of the beneficial effects that are observed with near infrared devices. Elsewhere, radiation is not strong enough to have the same effect.