2005 Nissan Micra temperatue light comes on when doing 60

Get a sniff test ( block test ) done if head gasket suspect .It will tell if gone or not .

heres a few good tips about blown cylinder head gaskets look in coolant expansion tank contents should be green not rusty and NOT oily, next undo oil filler cap and look underneath is there a a build up of what looks like mayonnaise? if the answer is yes to either of these symptoms you either have oil in the water or water in the oil or both which is indicative of leaking or blown cylinder head gasket BUT needs FINAL confirmation by a compression test of the cylinders themselves