This is a fat guy with his shirt off standing in his underwear. He also has a pulse oximeter. It measures your blood oxygen level by looking at the color of your fingernail. It shows that his blood oxygen level is at 89 percent. Anything 92 or below gets you an oxygen tank to roll around. He has interstitial lung disease. It is a little understood lung ailment that causes your immune system to attack your lungs with scarring. The scarring makes your lungs less effective at putting oxygen into your blood. Eventually you suffocate as it is an untreatable disease. Life expectancy is 2 years from diagnosis.