Palm Beach County is opening cold-weather shelters on Feb. 5, as a strong cold front moves across South Florida.

Another Arctic blast is expected to bring sub-freezing temperatures to Florida this week. See when the coldest temps are expected.

A second February cold front will assail Florida this week on the heels the previous punch of winter, which was still challenging records Tuesday with lingering frigid air.

When temperatures drop and remain near or below freezing, reptiles and amphibians — including non-native green iguanas — can enter a lethargic state in which they temporarily lose muscle control and appear “frozen,” sometimes even falling from trees.

Even South Florida, where winters are typically mild, saw temperatures fall into the low-to-mid 40s, with Miami forecast to hit 47 degrees and West Palm Beach expected to reach 42. Those conditions are cold enough to trigger “cold-stunning” in green iguanas, an invasive species common in the southern half of the state.

The arctic air will remain focused across the Plains, then shift to the Northeast throughout the week. Some cold air will filter south over Florida, and although it will linger through much of the week, allowing temperatures to remain below average, the coldest temperatures will just last one day, Tuesday, followed by a slow increase.

Florida’s rare cold snaps can leave iguanas frozen and falling from trees. Here’s the science behind the phenomenon and what it means for ecosystems.

Following a stretch of ups and downs and very cold temperatures, another drop in temperatures is on tap for Thursday night into Friday as