Yep, sure love our Mr Heater Portable Buddy. We have plenty of ventilation through the seams of the canvas on our boat, but it has O2 sensor and tip over switch. Works great. They are made for indoor use. Good idea to crack a window, though, just for extra safety. Remember to turn it up to high setting when first starting up, then after the ceramic glows orange, you can turn it down to low if desired. It sure takes the chill off and helps us defog the windows. Bottles of propane last a long time and there's NO SMELL.
Rick