Forecasters in Florida have warned iguanas may start falling from trees as temperatures plummeted in the sunshine state leaving the cold-blooded lizards struggling to move.
For the second time in a week, the National Weather Service of Miami-South Florida warned people to be aware of iguanas falling from trees during the unusually chilly cold period.
The east coast of the US is currently experiencing the effects of a winter storm, leaving many northern areas blanketed in snow.
The National Weather Service of Miami-South Florida said on Twitter: "A cold morning...not as cold as our friends to the north dealing with a blizzard...but we have our own lizards to worry about."
The lizards are cold-blooded, meaning their muscle activity depends on chemical reactions which run quickly when it is hot and slowly when it is cold.
The key area is when temperatures drop to below 5C, making it hard for the iguana to keep warm enough to maintain its grip on the tree and fall to the ground.
They often aren't hurt by the drop but will be left sluggish and immobile by the cold weather, often leading people to think they have died.
Authorities say if an iguana is found locals should make sure they're in a safe location on the floor and leave them to recover when the temperature rises, which is expected to happen late on Monday in Florida.Iguanas aren't dangerous or aggressive to humans, but they damage seawalls, sidewalks, landscape foliage and can dig lengthy tunnels.
The males can grow to at least five feet long and weigh nearly 9kg.
Female iguanas can lay nearly 80 eggs a year, and South Florida's warm climate is perfect for the prehistoric-looking animals.
Iguanas are native to Central America, tropical parts of South America and some Caribbean islands.
Iguanas are allowed to be kept as pets in Florida but are not protected by any law except anti-cruelty to animals.
They've been in South Florida since the 1960s, but their numbers have increased dramatically in recent years.