YAR HUSSAIN CAMP, Pakistan (Reuters) - Hundreds of thousands of Pakistanis have fled from fighting in the Swat mountain valley only to be subjected to a cruel onslaught from nature on the plain below.
More than 800,000 people have left their homes in the scenic valley of orchards, forests and bubbling streams since government forces began battling Taliban militants there late last month.
Most have sought refuge on the lowlands to the south.
But Pakistan is entering the hottest part of the year when the sun beats down from clear blue skies and lowland temperatures regularly exceed 40 degrees Celsius (104 degrees Fahrenheit).
"People are living in very harsh conditions under the sun, very hot sun," U.N. High Commissioner for Refugees Antonio Guterres told reporters in the Yar Hussain camp, northwest of Islamabad, on Thursday.
He called for massive international help to avert a tragedy.
Families huddled in whatever shade they could find at the camp where lines of tents have been set up on a dusty, treeless field. Children splashed their faces with water from a tank set up by the U.N. children's agency, UNICEF.
"Look at these tents and the place where they are set up," said Maryam Bibim, a 40 year-old mother of four. "Can someone from a cool region live here? There are no fans, no cold water, nothing."
"Do you want our children to die of heat stroke? Even at night my kids can't sleep because of the heat. They cry but what can I do? Where can I take them?" she said, holding a baby.
Swat was until recently one of Pakistan's main tourist destinations with fishing, golf and hiking in the summer and skiing in the winter.
The U.N. refugee agency said only about 80,000 of the displaced were staying in camps, with the rest living with friends, relatives, in rented accommodation or in "spontaneous settlements" that were springing up.
At one such settlement, people from about 85 families were camping out beside a road near the town of Mardan.
"We can't live in camps, they're so hot," said Saifullah Kasana as he stood beside the road.
"At least here we have trees which protect my children from the sun," he said. "I fled from my village to save my children and now you want me to let them die in the soaring heat?"
The U.N. refugee agency has opened stockpiles of supplies to help the displaced and has also airlifted in 120 tons of supplies including plastic sheets for shelters and mosquito nets.
Prime Minister Yusuf Raza Gilani warned that while the army would defeat the Taliban militarily, the country could lose the public relations war if it failed to help the displaced.
Pakistan does have experience of dealing with large numbers of homeless in cooperation with aid agencies.
About 3.5 million people lost their homes in an October 2005 earthquake in the northern mountains that killed 73,000 people.
Then the army led a successful effort to feed and shelter the victims through a harsh Himalayan winter, avoiding a feared "second wave of death."
Lieutenant-General Nadeem Ahmed, a senior army officer who played a major role in the 2005 relief effort, is overseeing help for those displaced from Swat.
One of his main problems this time looks set to be the heat, not the snow.
Writing by Robert Birsel; Editing by Paul Tait