Eight miles across five Independence Day parades, a heat index north of 95 degrees, and 77 years on the planet.

For good measure, Sen. Bernie Sanders threw in three field-office openings, each drawing hundreds, and a roundtable discussion on immigration, all during his two-day trip to Iowa. He had the most parade stops of any candidate swinging through Iowa for the holiday. One on Wednesday, two on Thursday morning and another two on Thursday afternoon.

“We’re ready to go!” Sanders roared in response to a reporter’s question after the fifth and final parade, and joking, “We hear there’s a half-marathon down the road.”

Sanders is the oldest person seeking the Democratic nomination. Former Vice President Joe Biden, who led last month's Des Moines Register/CNN/Mediacom Iowa Poll, is 76; U.S. Sen. Elizabeth Warren, who is also in the top tier of that poll, is 70. In a debate comment aimed at Biden and his four decades in federal office, U.S. Rep. Eric Swalwell of California pulled up a 32-year-old quote from Biden about the need to “pass the torch to a new generation.”

An energetic Sanders marched for most of the parades, walking back and forth to shake hands and wave to parade-goers in West Des Moines on Wednesday, and Slater, Ames, Windsor Heights and Pella on Thursday. He rode in a convertible Ford Mustang for a time on Wednesday and took to a golf cart during the afternoon events Thursday.

Some heckled, but most seemed excited to see a presidential candidate walk through their neighborhoods and towns and raced to pull out their phones for selfies or videos.

Gavin Norton, a 15-year-old in Pella, flexed and yelled in excitement after getting a photo and handshake with Sanders.

“I love Bernie, and it was surreal because you always see (candidates) on TV,” he said. Having Sanders come to his small town — and knowing it was the final stop on a four-parade day — made it extra special, he said.

Sanders called it a “great day,” and a chance to meet people who might not come out in other circumstances. He also talked about the dozens of volunteers at each stop who marched along, signing up supporters on the campaign's app and handing out stickers.

“That’s just a heck of a turnout of people willing to come out in the heat,” Sander said of the volunteers. “So we’re feeling really good about our grassroots organization here in Iowa, and I think we stand a great chance to win here.”

Parade watchers also noted the heat. Mike Nielson, 49, of West Des Moines and a self-described libertarian, called out for Sanders to watch out for the heat, and not to campaign himself to death.

“This is crazy that a man his age is running around out here in this heat,” Nielsen said. “I’m not going to vote for him, but now it kind of makes me want to have a beer with him.”