Carihuairazo, also written Carihuayrazo, is Chimborazo's little neighbor. It's name comes from "Cari" that means Man; "huaira" that means Wind and "razo" that means Snow of the indian "Quichua" language. It is said, from indian mythology, that Carihuairazo and Altar stood in a fight against the big and jelaous Chimborazo because of a romance with Lady Tungurahua. The majestic Chimborazo won the fight against these two that is why they are now with destroyed craters. Carihuairazo is a good acclimatization peak where you can practice some snow and glacier walking skills. In the last 15 years the glacier has lost the the bulk of it's mass. Another 10 years and the glacier will probably be gone. Climb it while you can! It's a beautiful area and a nice snow climb and rock scramble with a technical finish. The short length of it's standard route makes this a great "easy" peak especially for soloists.
From Quito travel south on the Panamericana. By bus you will want to go to the Terminal Terrestre and get a bus to Ambato. From Ambato travel toward Guaranda either with another bus or hire a camioneta. You'll need to leave this road at the Rio Blanco. There is a dirt road leading towards the twin peaks of Carihuairazo. Camionetas (pickup trucks) from Guaranda are expensive (they ask for $80 but it is possible to get them in the $50 range if you are clever). Do not expect the drive to know the proper drop off point! They all can get you to the vicinity but that isn't always close enough. It is possible to drive quite close to the mountain if you know the way. The trek from the main road to the base camp just below the glacier takes about 4 - 5 hours. The hike in from the closest side road is a bit more than an hour.
No permits and no fees to go to this mountain, but there is a vicuña reserve. Technically you should pay and have permission but there is nobody official to collect it. Local children in some nearby communities have already learned to cheat gringos and have been known to appear with a photocopied "permiso" and ask outrageous sums of money from trekkers or climbers. Obviously it is meaningless.
As neighbor Chimborazo, it can be climbed year round, but best months are June, July, late December and early January.
Camping is available all over and is free. I wouldn't feel 100% secure leaving my things unattended however. There is a lagoon and a liitle river that makes a nice spot. There is an unofficial hostel in the small community. You'll have to ask for it but it is cheap and safe. $5 gets you a spot on the floor and use of the kitchen.
Check out with locals if Tungurahua's ashes and eruptions have made recent changes to Carihauirazo's glacier and mountain conditions. The answer is probably not, but it isn't a bad idea to ask someone who knows. The location is near Ambato. For general route conditions the South American Explorers may have people that have climbed it recently among their members. They also try to keep a bulletin board updated with climbing conditions on the volcanoes in the Quito clubhouse. Generally you can get some free route information by asking at the various climbing agencies too.