Although most of the reptiles will likely survive this period of immobilisation, Ms Cohen said freezing temperatures were a threat to their survival and pointed to a cold snap in 2010 that wiped out a large number of the population.

“Cold is a very, very life-threatening thing for them because they are from parts of Central and South America close to the equator where it always stays very warm,” she said.

Green iguanas are not native to Florida, according to the Florida Fish and Wildlife Conservation Commission. They were accidentally introduced as stowaways in cargo ships and are considered an invasive species. They can weigh up to 17 pounds (7.5 kg) and measure over five feet (1.50 metres) in length.

These iguanas are not the first animals to suffer the cold this winter. Hundreds of thousands of farmed fish died from thermal shock in a lagoon in northwestern Greece after a heavy snowstorm crippled the country last week.