SANTA CLARA—The West Coast heatwave wreaked havoc on the 49ers’ practice schedule this past week, leading coach Kyle Shanahan to joke that he, like his players, will take intravenous fluids to rehydrate. “I still do it, if I had too much fun the night before,” Shanahan said.

The game against the Arizona Cardinals marked the second time this season that San Francisco (2-3) blew a double-digit lead in the fourth quarter to a division rival, having done it in Week 3 against the Los Angeles Rams.