Newton's law of cooling describes an object whose temperature decreases exponentially with time. Because of its many applications, it is a frequent topic of introductory physics labs. In this article, I describe an experiment designed for the freshman year algebra-based physics course that applies this law to answering the question, "Why don't small mammals live in the ocean?" The experiment is part of a process under way to include more biology-related examples in this first-year sequence to better serve and provide relevance to our biology majors, who predominantly take the course. The experiment focuses on scaling laws and modeling, and demonstrates the utility of physics in answering questions in biology.