Thank you for your question, Diana.
There are two occurrences of the abbreviation C for Celsius in your example. The first occurs in the midst of a sentence and is not followed by a period; and the second occurs at the end of a sentence and is followed by a period. The occurrence of C without a period in the midst of a sentence tells us that this print text is not using a period with the abbreviation C for Celsius. In other words, the period that follows after the second C is just for the sentence and is not for the abbreviation.
Thus, we need an ELI with all occurences of the abbreviation C for Celsius.
Please do post again if you have follow-up questions.