A humanitarian crisis in Gaza is depriving two million people of electricity, vital medical care and clean water in sweltering summer temperatures, the United Nations human rights office said on Friday. "We are deeply concerned about the steady deterioration in the humanitarian conditions and the protection of human rights in Gaza," UN human rights spokeswoman Ravina Shamdasani told a news briefing in Geneva, Reuters reported. Gaza has been under an Israeli blockade since 2007. Shamdasani said that at the height of summer, with soaring temperatures, electricity has often been provided for less than four hours a day, and never more than six since April. "This has a grave impact on the provision of essential health, water and sanitation services," she added. Families buy only enough supplies for each day as they cannot store goods in refrigerators, especially meat and dairy products. Hospital officials complain of acute shortages of medications. The Gaza health ministry says about 40% of essential medicines has run out, especially for patients with cancer, cystic fibrosis and kidney failure.