The 100-degree heat this weekend didn't just frazzle area residents, it took a toll on infrastructure, too.

In two separate incidents, the Hawthorne Bridge malfunctioned and rerouted more than 1,000 people, said Multnomah County spokesman Mike Pullen.

Alert: Hawthorne Bridge has reopened to traffic after a lift malfunction that closed bridge to traffic several hours today. Heat a factor. — MultCo Bridges (@MultCoBridges) June 24, 2017

The bridge was inaccessible for about three hours Saturday when the extreme heat expanded the steel-structure bridge, causing the guide wheels to run off-course and hit cables and metal as the bridge was being lowered, which tripped an auto-shutoff.

"Workers manually adjusted the bridge to give space beyond what we thought was the most it would expand, but it was not enough," Pullen said.

On Sunday, a fuse blew while the bridge was being lowered, leaving the lift suspended 64 feet above the road for about 90 minutes, Pullen said.

"While a fuse can blow any day of the year, (electricians) do believe the heat had something to do with the blown fuse," Pullen said. "We'll spend this week seeing what preventative measures we can take.

"But I think it's a sign of global warming," he said. "I don't think they had many 100-degree days in 1910 when the bridge was built. This has been a problem occasionally in the past, but this is pretty early in the year."