Unplug that cord immediately.

A warm extension cord means it’s carrying more current than it’s rated for, or there’s damage causing resistance. Either way, it’s a fire risk.

The cord should stay cool — slightly warm in extreme sun maybe, but not hot to the touch. If it’s warm, you’re either overloading it (too many devices, or one big one like a space heater) or the cord is old, pinched, or has a bad connection.

Unplug it now. Check what’s plugged into it. A 16-gauge cord can only handle about 13 amps. A space heater alone pulls 12.5. See the problem? If the cord is undersized, get a thicker gauge (shorter and lower number). If the cord looks fine, move the load to a different outlet.

This is not a “keep an eye on it” situation. Warm cords catch fire.