The results are presented of 2 field seasons of research on Lake Tuto, NW Greenland, and the specific thermal environment, forms of ice, conditions of gas exsolution, and special conditions of ice waste are discussed. Special forms of ice and coarse air inclusions called worm bubbles are reported. An observation of ice waste from the upper surface at low temperatures is attributed to a combination of sublimation and abrasion by blowing snow. Temperatures in the 2-m thick ice cover, as well as in water, were observed during ice growth. These and other observations suggest that sunlight is the main heat source and the sun penetration of the ice may raise the water temperatures an appreciable degree. It was found that the lake water contains 3% to 4% gas while the ice contains 0.5% of dissolved gases of a composition probably differing from that of the air. Existing theories of solute rejection by the moving solid-liquid interface are found inadequate for the case of the ice-water-gas system. It is concluded that worm bubbles may form by a mechanism other than nucleation at the interface. (Author).