0+ is a very cold day.
N.B. subjective interpretation of temperature affected by locale of reference.
0+ is a cool to chill day, but still acceptable shorts weather if you don't plan to be outside for extended periods of time.
Personally I use feet, inches, and fractions of an inch for construction. But I only do that because 90+% of building materials sold in Canada are still cut to Imperial measurements. (This is for economic reasons. Mills producing stuff here can then produce the same stuff and ship it down to the US Market, and we can buy materials off the US Market without getting weird looks when we ask for something in cm.)
The moment metric cut materials become common here, I'll toss my imperial tapes in the back of the tool box and forget about them.
If you're tapes don't have metric and imperial measurements, you bought the wrong ones. I haven't purchased a ruler or tape measure without both since I was in kindergarden. Even my Gerber multitool which has barely enough room to write the numbers has metric and imperial units.
No, I very much bought the correct tapes, scales, and rulers. The first thing I do when I get a tape that has both metric and imperial is toss it out and go looking for a real tool. A dual marked tape is a tape that you can only measure from one side of.
When you measure for construction or drafting, you measure from base lines. If you have your tape hooked at the base line and are marking out points on the floor, then a double scaled tape means that you possibly have the wrong scale against where you are marking, and then you're kind of eye balling your lines.
For what reason would you ever want
both imperial and metric at the same time? I've been around construction sites since I was about 5, and in those 20 years I've yet to use a metric tape on a job site for anything other than assembling precision equipment that was designed in metric.