How to cool down DIP devices?
With the much reduced use of DIP ICs, few component retailers offer DIP heat sinks any more (and possibly few of the younger electronic circuit designers know about the stuff!). However, if you are looking at personal / DIY use, glue-on DIP heat sinks in anodized aluminium are available, often as "new old stock", on sites like eBay, and surplus vendors. 

For instance, I found this on eBay for under $1:



While it is designed for 14 to 16 pin DIPs, it is trivial to chop it down the middle and use half for an 8-pin DIP. 

Thermal paste between the heat-sink and the IC would be useful, or one could use peel-and-stick thermal paste pads for convenience:



Some form of clamp would also be needed to hold down the heat sink, if glue-on isn't good enough.

Alternatively, 2-part and slide-on heat sinks for DIP used to be quite common, and can still be found as "new old stock". These eliminate the need for a clamp:



However, these heat sinks are not as convenient to use for a smaller DIP, such as an 8-pin package. 

Finally, sometimes one would sand the face of a metal coin flat, then clamp it onto a DIP IC, as an interesting-looking heat sink. End of history lesson :-)