Orange light appeared last night round symbol with exclamation mark inside. Lost all power but could still just about drive home. Has not come on this morning and power seems fine. What should i do?

I would suggest hooking a mechanical oil pressure gauge to the engine to confirm that you do not have a low pressure condition when the engine gets fully up to operating temperature.

TRANSAXLE warning light (exclamation mark inside a gear symbol)
Indicates problems with transmission.

The first thing to check is the level and condition of the transmission fluid. Possibly as simple as low transmission fluid, but it may be a serious transmission fault.
The high RPM sounds like the transmission is slipping.

Mechanic will be able to read the codes and tell you what is wrong.

If it's an exclamation point inside a triangle, it's called a master warning symbol. This is the Master Warning Light symbol. If this light is on, there will likely be text displayed as well on the instrument panel, or another warning light. Look for text in particular. It could very well point out something as serious as low oil pressure. If the engine is not running, you can't very well check your gauges, but you may have lost all oil pressure or overheated the engine. Recommend you consult a mechanic familiar with your model.

This is NOT a Tyre pressure sensor warning!
Don't know why people post this when they haven't got the foggiest idea.
It is a fault associated with the drivetrain which includes from the injectors on the engine to the transmission and possibly just a sensor malfunction.
There are multiple errors possible with this fault.
Requires a diagnostic OBD2 port analysis of the ECU to clear the fault codes and further analysis.

Google the kind of car and it's year. Add the word ...dash symbols.

time for a service. or oil to low. time to top up.

There are two symbols with an exclamation mark. The first is a oblong circle with the exclamation mark inside with ( ) on each side of the oblong circle. That symbol is for brake system warning light. Check brake fluid level, check brake pads. The other symbol is (!) and is flat on the bottom its suppose to resemble a tire, it means there is a problem with the tire monitor system, check your tire pressure, if you have low tires you will have to drive car after servicing the tires then the light should go out. Tire pressure should be on a placard on the driver door or door frame.

That symbol is the Low TIre Pressure Warning. It tells you that your tire pressures are low.

It is the Tire Pressure Mounted System (TPMS). It monitors the air pressure in your tires. If it is on, you have low tire pressure...or like me, it's just a faulty indicator. Mine came on, but I don't even have TPMS on my vehicle.

This light is for multi funtion automatic transmisson cooling system