The body will not get oxygen if what system fails

I would say the respiratory system (the lungs) fail. The lungs are to receive oxygen and it sends it to the heart.

I am not much of a biology nerd but I am taking an educational guess.

All I can say that the lungs need oxygen. Without oxygen, the heart will stop pumping blood and you will be suffocating with this essential. That is why you should never smoke and actually take great care of your precious body.

If body temperature rises, blood vessels in the skin dilate, allowing more blood to flow near the skin's surface. ... Conversely, if your body is too cold, blood vessels in the skin contract, and blood flow to the extremities (arms and legs) slows. Muscles contract and relax rapidly, which generates heat to keep you warm.