Is it safe to leave food warming for hours before I eat it?
It is, if you start it right. Bacteria multiply fastest in the temperature range between refrigeration and proper hot-holding, and the general food safety guidance is to move food through that range quickly. A conduction warmer takes longer than a microwave by design, so start from properly chilled or frozen food rather than a meal that has been sitting in a warm bag since breakfast. The clock starts when the food leaves the fridge, not when you plug the device in, so a morning in a hot car followed by a slow warm-up is the combination to avoid. Keep the meal refrigerated at work if a fridge is available, and plug in an hour or two before you eat. Once hot, HOTLOGIC designs it to hold food at temperature, so leaving it plugged in until you eat is correct use; just reheat food once, not repeatedly.
Can I use it in my car or somewhere with no plug socket?
Only where you can supply 120V. The Mini has no battery and comes with nothing but the tote, so on the go really means anywhere you can plug in: an office, a break room, a site cabin, a hotel room, a workshop or a classroom. It works in cars that have a suitable outlet, and abroad you may need a power converter. It will not work on a beach, on a train or on a site with no power, so check that before ordering if that is where you plan to eat.
Why is my food only warming on one side?
Almost certainly the container. The whole method depends on contact with the heating plate, and a curved or ridged base leaves an air gap that heats slowly and unevenly. Shape matters too: tall, narrow containers heat poorly compared with wide ones that cover the plate. Use a flat-bottomed, wide container in glass, plastic, metal, foil or a cardboard tray and the problem should disappear.
My lunch box lid won't close inside it. What's wrong?
The height limit is 2.5 inches, and it is the measurement people most often fall foul of, since plenty of ordinary lunch boxes are taller than that. A bag that will not close lets heat escape and slows the warm-up considerably. Measure a container you already own and would actually use before ordering, rather than assuming your usual box will fit.
How long does it actually take to heat lunch?
Longer than a microwave, by design. Cold food typically comes up hot in roughly 40 minutes to an hour, and heating time is its one mixed point, so you may need to switch it on well ahead. Plan to plug it in mid-morning so lunch is ready by the time you break, the same way you would plan a slow cooker. Expect microwave speed and you will be disappointed; plan around the slow warm-up and it works exactly as intended.
Can I cook raw food in it, or only reheat?
Both, for the right foods. HOTLOGIC says it can cook as well as reheat, and pitches it for healthy dishes and frozen boxed meals as well as leftovers. Slow, gentle heat suits dishes that would work in a slow cooker. It is not a substitute for fast cooking methods or for foods that need high heat, such as searing or crisping, and anything raw should be cooked right through before you eat it.
