The Liquid Cooling and Ventilation Garment (LCVG) is the innermost layer of an Extra Vehicular Activity (EVA) suit. The LCVG’s purpose is to provide the needed cooling for astronauts when exposed to the extreme environments of outer space. The main cooling is achieved through the circulation of cold water through Tygon tubing woven into the fabric of the garment. Gas is also vented through the garment to aid in cooling and sweat evaporation. The cooling distribution is designed for sufficient cooling on Earth.
STS097-327-033 (30 Nov.-11 Dec. 2000) — Astronauts wearing the liquid cooling and ventilation garment (LCVG) before putting on their extravehicular mobility unit (EMU) spacesuits for a spacewalk. Photo Credit: NASA.
Many astronauts do not utilize these cooling capabilities, even on the lowest settings. Often the current LCVG renders an astronaut feeling too cold, particularly in their extremities. It is believed this cooling effect is due to the effects of the cephalad fluid shift in a microgravity environment. The shift reduces the blood circulation to the legs and therefore decreases the heat rejection capabilities of the legs.
Lexi Heininmann is currently working on determining the effects of microgravity on the human thermoregulatory system for both genders via infrared imaging.