Especially in the biological and medical fields, 1°, 2°, and 3° are common abbreviations for primary, secondary, and tertiary (but this is actually the "masculine ordinal indicator" not a degree symbol). In medical shorthand, the degree symbol is also used to denote hours, for instance q4° or q4° meaning "every four hours."
In contrast to expressing degrees of arc, in the case of degrees of temperature, two scientific and engineering standards bodies (BIPM and the U.S. Government Printing Office) prescribe printing temperatures with a space between the number and the degree symbol, as in 10 °C. However, in many professionally typeset works, including scientific works published by the University of Chicago Press or Oxford University Press, the degree symbol is printed with no spaces between the number, the symbol, and the C or F representing Celsius or Fahrenheit, as in 10°C. This is also the practice of the University Corporation for Atmospheric Research, which operates the National Center for Atmospheric Research. Others put a space between the degree symbol and the letter (10° C), which is probably no longer recommended by any of the major style guides.
Due to a similar appearance in some fonts in print and on computer screens, some other characters may be mistakenly substituted for it: the "masculine ordinal indicator" (U+00BA, º ), the "ring above" (U+02DA, ˚ , which appears on a Mac keyboard layout at
K), "superscript zero" (U+2070, ⁰ ), superscript zero proper ( 0 ) or superscript letter "o" ( o ), and the "ring operator" (U+2218, ∘ ).