2015 ASHRAE Handbook -- HVAC Applications Heating, Ventilating, and Air-Conditioning Applications (I-P) - (includes CD in I-P and SI editions) (Ashrae Applications Handbook Inch/Pound

Laugh and cry. Having a good sob is reputed to be good for you. So is laughter, which has been shown to help heal bodies, as well as broken hearts. Studies in Japan indicate that laughter boosts the immune system and helps the body shake off allergic reactions.