Because he obviously got the airborne disease from someone else and is therefore got it from someone else and is considered "exposed" and should be treated so
If the disease is communicable, it is contagious. If it is airborne, it is transferred through the air, as opposed to physical touch or blood-borne. Being in a confined space, such as an ambulance, with an airborne communicable disease means you have most definitely been exposed to it.
Physical activity is helpful for your heart muscle and also strengthens your immune system also good for your lungs and helps maintain your weight <span />
Say you would want to start eating healthier. You ask your parents or whoever goes grocery shopping in your family to buy less junk food and more healthy food. You can also ask them to keep you on the right track. Since there is less junk food in your house, your family would theoretically start eating better too.