Freezing
Shepard had been underwater for over an hour now and Cortez still couldn't get a stable signal connection to contact her. Garrus was getting worried. She'd gone down in the Triton mech so she could search for Leviathan. According to the schematics, Leviathan was underwater.
Just when Garrus thought she wouldn't be returning, the Triton burst out of the icy sea. He saw Shepard exit the mech but once her feet hit the deck of the ship, she collapsed and didn't move. Something was wrong. Tali covered him from the Reapers as he hurried over to retrieve her.
On the shuttle, Garrus' scans from his omni-tool indicated Shepard was partly hypothermic. Her skin was pale, her lips partially blue and she was unconscious. Garrus called out to her to wake up. What did Leviathan do to her?
As if on cue, Shepard awoke, coughing and like she had swallowed water. Garrus grabbed her and pulled her close, whispering that she was safe. Shepard calmed and relaxed in his arms.
Garrus continued to hold her until she stopped shivering.