If your vehicle is showing floorboards feel unusually hot to the touch while driving, here are the most likely causes and the parts you'll need to fix each one.
Heat shields are designed to block the intense heat of the exhaust system from reaching the cabin floor. They frequently rust off or are intentionally left off by mechanics after exhaust or transmission work.
If the engine is running rich or misfiring, unburned fuel enters the exhaust and ignites inside the catalytic converter. This causes the converter to glow red hot, transferring extreme heat directly through the floorboards.
A leak in the exhaust manifold, flex pipe, or exhaust gaskets can blow hot exhaust gases directly against the underside of the vehicle's floor, rapidly heating the interior.
A transmission running too hot due to low fluid, heavy towing, or a failing cooler will radiate massive amounts of heat through the transmission tunnel into the floorboards.
If the heater core leaks, 200-degree engine coolant can pool underneath the carpet on the passenger side floorboard, making it feel hot and damp.