Assistance programs are offered by many gas, electric, water, and phone companies. If you feel you may have difficulty paying your monthly bills, contact the company before your balance becomes too large. Companies are more amenable to working out a payment plan with those willing to work with them.
Many states have regulations that prohibit companies from turning off utilities; your doctor or social worker may need to write letters describing why the service(s) are medically necessary. The regulations do not diminish your responsibility for paying the bills, but may allow you more time or lower monthly payments.
In an emergency situation, check with local help lines and social service agencies as some provide one-time emergency help with utility bills.