Oxfam said it expected temperatures in the Middle East to reach 100 degrees Fahrenheit in the coming weeks. Regional Oxfam coordinator Rick Bauer said that will strain the capacity of humanitarian agencies working to address those people displaced by conflict in Syria.
"We are starting to really worry about the health of Syrian refugees," he said in a statement. "Too many are living in inadequate shelters such as an empty shopping center or the outskirts of a cemetery."
The U.N. Refugee Agency last week said the Syrian war has forced 1.5 million people to flee the country. The agency said the actual number of refugees is likely higher as aid workers have registered about 250,000 people as refugees each month this year.
"The sad reality is that the vast majority of Syrian refugees are not going home soon," Bauer said. "It is also crystal clear that host communities in Lebanon and Jordan need urgent help."
Oxfam said it has received about one-quarter of the $53.4 million it was seeking to raise for 2013 relief efforts in Syria.
The United Nations estimated that 80,000 people have died in the Syrian civil war, which began in early 2011.