ORANGE CITY, Fla. —  It's a sure sign of cooler weather when manatees show up at Blue Spring State Park.

Officials at the park spotted 58 manatees on Sunday, up from 27 sea cows on Saturday.

When temperatures get really cold, hundreds of manatees can be found at Blue Spring.

Water temperatures at the springs are at a constant 72 degrees, and manatees start to deal with cold stress when water temperatures get 68 degrees or cooler. 

Cold stress makes manatees vulnerable to disease and even death. 

So manatees will gravitate to warmer water from springs, canals and even power plants, and keep close to each other to stay warm. 

The Florida Fish and Wildlife Conservation Commission urges boaters to stay away from areas where manatees gather for warmth, because that can make them leave the warmer water and put them at risk of exposure.

Coincidentally, November is also Manatee Awareness Month.