Yes, they both need heatsinks (3 on the Pi, 2 on the RB). I also added fans. I use an open case, i.e. plexiglass top and bottom with threaded spacers at the corners (https://smile.amazon.com/gp/product/B074T7D1V5/
). I ended up using a "fan hat" GPIO extender board (like https://smile.amazon.com/gp/product/B09MVL8BWQ/
) to cool the Pi -- The extender fan board is inserted between the Pi board and the RB hat. My RB (purchased recently via Aliexpress) came with a heatsink that has an integrated fan, but you could just as easily drill out some holes in the case top and mount a fan there.