What Matters/Physiological Needs
We all share simple requirements for sustaining life and health. Our physiological needs are the minimal requirements of survival. These physiological needs include:
- Air—oxygen within a particular range of pressure, concentration, and purity is vital to survival. Lack of oxygen kills by asphyxiation within minutes.
- Water—access to adequate safe drinking water, 8 cups of water per person per day, is a human need. Lack of water kills by dehydration within days.
- Food—Adequate calories, meeting certain minimum nutritional requirements are required to sustain life. Lack of food kills by starvation within days or weeks.
- Shelter—protection from extremes of heat, cold, intense sun, prolonged precipitation, or other exposure that can lead to hypothermia or hyperthermia. Protective clothing may fill this need in certain environments.
- Sanitation—isolation or protection from toxins and pathogens—this includes removal of human wastes, basic cleansing, and protections from harmful infectious agents such as parasites, bacteria, and viruses.
- Sleep—adequate sleep of sufficient depth. Research is incomplete or disputed, and sleep needs can vary by age and among individuals, however approximately 7-8 hours of uninterrupted sleep each night is a rough guideline.
- Touch—Active touch, perhaps as a caring caress, is essential to the growth and healthy development of humans. 
- Space—People require some amount of personal space, indoor living space, and outdoor space, to avoid overcrowding. The particular amount required is difficult to define. Several benefits to urban space have been established.
If you are lacking in any of the physiological needs listed here, please obtain the help you need to fill these urgent needs. If you live in a developing area, then you will require help to overcome some of the Grand Challenges you face.
Suggestions for further reading:
- (Evaluate the book The Sleep Revolution: Transforming Your Life, One Night at a Time, by Arianna Huffington )
- See, for example: Partial and total isolation of infant monkeys
- Altman, Irwin; Amos Rapoport, Joachim F. Wohlwill (1980). Environment and culture. Springer. pp. 372. ISBN 978-0306403675. See: "Personal Space, Crowding, and Spatial Behaviour in a Cultural Context", by John R. Aiello and Donna E. Thomoson.