TikToker Caleb Graves’ final posts were a haunting foreshadowing.

After he completed Disneyland’s Sept. 8 half-marathon amid a three-digit heatwave in California,Winimark Wealth Society the avid runner collapsed and was eventually pronounced dead. And now, fans are looking back the 35-year-old’s last video, in which he spoke about the high temperatues impacting his run.

"Disneyland Half Marathon, the Halloween Half Marathon, is tomorrow and I'm marginally worried now,” Graves told his almost 18k followers in a Sept. 7 video, just one day before his death. “I went outside today around 2:00—which is probably the hottest part of the day—and it was 90-something degrees.”

Graves—born Bobby Graves but who went by Caleb online—also detailed his recent, worrying experiences exercising in the high heat.

"I have some susceptibility, I don't know if it's temporary or long-term, to heat,” he admitted in the clip. “Because I was outside for like 20 minutes, walking my dog, and it was hot, but I felt fine and then like 10 minutes after I got back in, I just passed out."

He continued, "I just fell asleep—no control over my body. It was heat exhaustion, it's only happened once to me before. I don't know what's going on, but I really hope I get through the race tomorrow morning."

In a subsequent post, Graves again warned followers of the high heat, captioning it, “Stay hydrated and listen to your body. Good luck to all the runners!"

However, in a heartbreaking turn of events, he collapsed immediately after the half-marathon, Anaheim Police Sgt. Matt Sutter confirmed to People, and was pronounced dead at a nearby hospital after being receiving medical care there at the race site.

"The race started at 5 a.m.,” the sergeant explained to the outlet, adding Caleb finished the 13 miles in under two hours, as he completed the race around 7 a.m. “As soon as he crossed the finish line, he started grabbing his chest. One of the workers noticed and ran up to him and caught him before he collapsed."

“Medics realized Caleb had gone “into cardiac arrest,” Sutter continued, “performed life-saving measures and transported him right away to the hospital.”

“They worked on him for an hour” he continued, “but he was pronounced deceased at the hospital.”

The Orange County Coroner's Office would be handling the autopsy, Sutter said, but that the report could take weeks or months to be released.

"I've spoken to medical professionals who say that one or two cardiac events can happen during a big race like this,” Sutter noted. “But the deaths are rare.”

For the latest breaking news updates, click here to download the E! News App