How do you control the increase in engine temperature even when the cooling fan is working?

You have several options. 1. check that fan is coming on at correct temp. If too high replace sender / control unit. 2. If correct but because of use/ambient temp vehicle is still running to hot then following are pos. A) If a temp thing (going up a mountain etc.) turn heater to full put blower on max. B) For long term you need to obtain a temperature adjustable control unit (auto electricians) so that you can lower temp which fan cuts in at - this will also increase duration of fan use. C) Obtain specialist fan with better cooling properties than orig (Kenlow ).