Given you just had work done done on the car I'd say the ambient sensor is unpluged ( it should be the little black lump next to the horns, behind front bumper).
Like GTScotT said its a common thing, mechanic forgets sensor, A/C thinks the outside temp is -40C or something and fires up the heater 4 ya
There are 2 other sensors, one at the back of the dash ,left side (sunLoad) and one just to the left of the steering columb (interior temp).
Any of these left unpluged/faulty will screw up ya AirCon (usually with the heat your gettn)
Cheers
EDIT: Water temp hitting 110C sounds like a seperate issue, I THINK this is a common issue 4 workd motors (I'd sujest you search SAU 4 this one, I've seen a few good posts covering this)