About 300 people, most of them Scouts, suffered from dehydration, fatigue and lightheadedness Wednesday — just days after four Scout leaders were killed at the national Jamboree while pitching a tent beneath a power line.
Temperatures at Fort A.P. Hill, an Army base where the 10-day event is being held, reached the upper 90s and were intensified by high humidity.
"This is hot for me," said Chad McDowell, 16, who lives in Warrenton, Ore. "Where I'm from if it's 75, we think that it's a heat wave."
Mr. Bush had planned to visit the Boy Scout jamboree on Thursday, but postponed his trip again,.
On Thursday morning, White House press secretary Scott McClellan said the Scouts had asked the president to put off his appearance yet again, until Sunday.
"This is a large crowd," McClellan said. "I think part of it was they just wanted to make sure they had all the medical supplies and EMT personnel to handle such a large crowd. It's as simple as that. A lot of it had been used previously."
Half of the 300 who fell ill were treated and released from the fort's hospital. Dozens more were sent to surrounding hospitals, where they were in stable condition Wednesday night, Jamboree spokesman Gregg Shields said.
The more than 40,000 Scouts, volunteers, and leaders attending the event had been standing in the sun about three hours when word came that severe thunderstorms and high winds were forcing the president to postpone his appearance until Thursday.
At the last jamboree four years ago, Mr. Bush's trip was also canceled because of bad weather, in which lightning strikes caused minor injuries to two Scouts. He spoke to the group a day later by videotape.
This time, Mr. Bush was expected to talk about the importance of Scouting and touch on the Monday deaths of four Scout leaders.