Do you have anything connected to it? Or just the bare module.
I suggest to disconnect the module, wait for it to cool down, and plug it back in. Use your fingers (veeeeeery carefully) to find where the heat is coming from.
You could also look round the board, and check for accidental shorts, and solder bridges. This may cause problems.
When trying to find the heat source:
Schematic:
https://wiki.wemos.cc/_media/products:l ... v1.0.0.pdf
Check the components around the USB jack first, if they get hot. There is a MosFET and transistors(Q3 and U2) which should open fully if you plug in your USB supply, and should close if you power the board from external 5V (so you don't back-charge through USB).
Here if there is heating, either the mosfet is not fully open or the transistors are not opening. Check also the resitors if the intact or not broken.
You can also check if the heating is still existing, when you power the lolin from an external 5V, not through USB.
Check also the LDO (U3) which supplies all 3.3V parts, like the ESP32. If it's hot, that something is consuming more power than it can handle, which is not a good sign (or the LDO is either too small for the load, or faulty).
Finally, if you have a multimeter, and you can supply the board with 5V externally, use a Multimeter to measure current (set the multi to 10A, and connect it in seireis between the power and the pin).
If you measure around 1A, or between 0.5 and 1A, when plugged in, that's not good. If that is the case, let us know.
(And I also put here and on fashioned joke):
Keep note, that like most IC-s and electrical parts, this also operates on smoke. If it leaks from the component, this means that the component is leaking it's fuel and replacement is needed.
