Hapa sidhani kuna ujanja, you just have to contact your mechanic roho safi, D-I-Y ni ngumu. It could be something as simple as some sensors that require servicing or the more complex (and hopefully not) cracks in your cylinder head that may necessitate its replacement. Some of those hirline cracks are pretty difficult to spot. Or it could even be a simple cylinder head gasket that requires replacing, or the water pump might be faulty, etc.

First verify that all your gauges are actually working. If they are, then I think you have no worries at all. I have only ever come across two cases where engine was overheating (coolant wa actually boiling) yet temperature gauge was normal. I'm told that can happen in case coolant level is insufficient (investigate for leakage, if any). In both cases, the fellows ended up having to replace cylinder heads (one had some very fine hairline cracks, the other had some obvious ones).

In the same breath, you may wanna avoid this idea of car wash guys literally washing your engine with that pressurized water thingie. Water can easily get into some electrical connections and stall your engine.

If engine has been running for a while, e.g on a long journey and you notice coolant is insufficient, let it air-cool on it's own (usually about 8hrs) before adding cold coolant/water.

That said, pay a visit to your mechanic just to be sure. All the best pal.

There is a very narrow gap between the two. I have been down that debate with friends. Would be interesting to get wazuans opinion. Even google will have very extreme opinions... But generally in favor of "let the thermostat stay in there