Studies of the physiological response of human half-body illumination by a specially designed bed comprising large number of LEDs emitting in the red and near infrared spectral range were carried out in a group of 32 volunteers comprising healthy subjects and hypertension patients. Blood pressure, heart rate and arterial blood oxygen saturation, as well as the bed surface temperature were continuously monitored during the measurement sessions with and without aluminum foil cover on the bed surface. None of the volunteers exhibited any notable changes in the heart rate and blood oxygenation during the procedures. The LightStim LED-bed session did not produce changes of arterial pressure in normotensive group, while decreased blood pressure exhibited 2/3 of hypertensive patients. The thermal emission from the bed may serve as a dominant contributor to the observed effects on cardiovascular system.