I came across a story today about a Texas windsurfer who heroically rescued a green sea turtle (Chelonias mydas). The turtle was one of many in the area that had been stunned by a recent cold snap that affected water temperatures in the Laguna Madre.
Adult green sea turtles are herbivores that mainly eat seagrass.
Green turtles are happiest in water warmer than about 20 Celsius (68 Fahrenheit), but they can tolerate somewhat colder water, at least for a while. If it gets as cold as 8 Celsius (46 Fahrenheit), however, they can barely swim, and they will die if it doesn't warm up. Usually the turtles flee if it starts getting too cold where they are, but in a shallow bay, like Texas' Laguna Madre, the water temperature may drop faster than the turtles can find their way out to warmer open water.
Although animals being killed by extreme hot or cold weather is a normal part of nature; one of the mechanisms that sets the geographic range boundaries of particular species, it's sad when it affects critters like the green turtle, whose populations are struggling to recover from human impacts like overhunting, loss of nesting habitat, and plastic ocean trash. So I don't think it's "unfair" for people to intervene by assisting such endangered species when they're caught off guard by something like a cold snap. In fact, it's awesome.