It’s late March at Gale Crater, the landing site of the Mars Curiosity rover. And according to the Mars Weather site, temperatures haven’t made it above freezing for weeks.
It’s a cold spring for Curiosity after a surprisingly warm winter. But the engineers knew what they were getting into when they designed the rover. They knew its systems would need to endure temperatures colder than -150 degrees Fahrenheit, and that they would need to operate reliably without much time above a balmy 32 degrees.
The same basic principle applies to any future human habitats on Mars. But in addition to sporting systems that can withstand harsh, fluctuating temperatures, a habitat must also survive a journey to and a landing on the planet, keep its inhabitants protected from harmful radiation and a toxic atmosphere (or lack thereof), and maintain comfortable indoor temperatures.
Speaking from experience in a simulated habitat I can tell you: Shirtsleeve temperatures are preferred.