engine overheating

most of you know that i jus got this car 2 weeks ago. I drove it 45 miles back to my house with no problem...
so jus got my car back today, from getting the power steering and the exhaust fixed(both under the car, and not under the hood) and now the engine is overheating, BAD like coolant boiling... i dont really see how the repairs i got done could affect this, so could it be from sittin outside the shop without being started for a week? seems really sudden, since it went from not reading hot one week to reading OVER the redline on the temp guage the next. AC has been off the whole time.
so only things i can think of are... thermostat isn't kicking fans on soon enough( i kno they're workin, but not till it is already hot it seems)

clogged coolant hoses

or just horrible coolant.

any other ideas? im doing a coolant flush tomorow and im going to pull whatever hoses are easily accessible and make sure theyre not clogged.
i hope this fixex it, but i need to kno wat else could cause it.
The car is a 93 vr4. are there any hoses that are known to clog easily?
what could cause it to be fine one week, and bad the next? Help! pls, Thanx Ryan

it might be your thermastat.. it doesnt turn on your fans.. it lets the coolant move through out the whole engine and back out the the radiator

how do i test that? i had to pull over every half mile or so i could let it cool down to get the car home tonight... where is the thermostat?

Its in the water inlet.. where your upper radiator hose conects to the engine.. its an easy and cheep fix.. there like 8 bucks at auto zone.. and I think it came with the gasket.. you will want some coolant also