what do they look like? they are probably a derivative of birdseye's as they are the most commonly grown hot chilli. and can get fairly hot
the scoville scale is the rating of chilli heat, based on the actual capsicain (active ingredient) found in the chilli
now keep in mind that PURE capsicain (ie the hottest thing on earth) = 16,000,000 scoville units
from what's generally available in this country there are:
jalapeno: around 4,000 SCU - roughly the same as tobasco
long red: ~50,000 SCU great to use as you can smash HEAPS into food to get the chilli flovour without going to the heat of birdseyes
birdseye:: ~100,000 SCU hot
scud chilli (green thai chilli - prik) ~ 300,000 SCU (once had a dish at work with 40 of these and i could actually feel my stomach burning for about 30 mins after ) these guys are seriously hot
habanero: - 500,000 SCU - the hottest i can eat straight (not fun) - and the main ingerdient in the best mexican hot sauce available - el yukateco! these guys have the best flavour of all the chilli's available, if you can get past the heat they have an amazing floral property to them. kinda hard to describe though
from serious specialists you can get:
bhut joloka (ghost chilli) ~ 1,000,000 SCU i have not eaten one yet... and doubt i could hande a straight one, but am assuming i could have one in food as i have had sauce made from these, (and it was terrible, not just the heat... the taste!) this was the worlds hottest chilli for years.
and finally...
The TRINIDAD SCORPION (Butch T pepper) - 1,400,000 SCU: 3 times the heat of a habanero... no fkn thanks! the worlds hottest chilli... grown in Australia.
and FWIW polce issue capsicum spray is usually around 3,000,000...