Mazda Repair Questions? Ask Mechanics for Answers ASAP
This all points to a snapped or slipping Alternator Drive Belt. Check the Belt initially. If it is snapped then a replacemtn will be necessary. Prior to fitting check that all of the pulleys are free to turn (alternator, water pump, guide pulleys etc.). If any of the pulleys are seized then this could be why the belt has snapped! Rectify as necessary and fit new belt.
The belt drives the water pump as well as the Alternator hence the High Temperature Reading so as such the vehicle shouldn't be driven until repaired.
You are looking at approx 45 minutes to change an Alternator Belt. That would equate to something in the region of £90 plus vat in labour plus the belt which I would think will be somewhere in the region of £30.
There is no Timing Belt on these engines. It is Chain Driven and there is no recommended interval for a chain. Basically if you are having the oil and filter changes done as per Mazda Service Schedules you should have no problems with the Chain. They are usually only changed if it starts rattling!