Welcome to AllNurses.com! I see that this is your first post here.
By the nature of your questions, and the way they were worded, it sounds like you have some homework to do. We are happy to help you with homework, but we won't just give you the answer. You will learn much more by researching the topic yourself, posting your thoughts and the information you have found, and asking for clarification.
Question 1: The insulin you administered is "rapid acting." What does that mean? Look up the onset, peak and duration of rapid acting insulin. Remember that onset means when it starts working, peak means when it's working the most, and duration means how long it will continue to work. You'll want to check the blood sugar at the peak time- when the risk of hypoglycemia is the highest.
Question 2: What do you think? What do your text books say? If you give heated oxygen, what part of the patient will you be warming up? What about with heated IV fluids? Are there risks involved with either method? Research both of them, and let us know what you think would be best, and why.