Chicks - what next?

I hatched out chicks in an incubator 4 weeks ago. Normally I leave the broody to do all the hard work, but neither of my Silkies would perform this year. Hence the incubator. I have been progressively raising the heat light off them, and they are growing at a rate and starting to feather up nicely. I know in the past my broodies have been out and about during the day with their chicks from a very young age - but with incubator raised chicks at what point would you put them outside during the day, and at what point would you take the lamp off them, full stop? I am a bit precious with this lot, as I have done all the work and if one of them dies it will be entirely my fault, whereas with a broody I have to leave it to nature (and nature usually works very well!)

I bought my chicks as day olds and they went outside off heat at 33 days.

However they are fully feathered (no fluff left).

I'm paranoid about losing my incubated chicks as they don't have mum to protect them.  I generally wean mine off heat by 6 weeks (later over the winter, earlier in the summer if it's warm enough) and as long as they are feathered and eating growers pellets I put them outside soon after that.  I have had some of my bantam chicks taken by the crows so I like them to be big enough not to be crow-lunch, as well as able to deal with the lovely British summer weather (i.e. rain!)

Some breeds feather up earlier than others so that might also affect your decision.

Sarah 

Mine are 3 weeks now and I've started putting them out into a secure run for an hour a day when the weather's warm. They have been loving the experience and it's given the other girls a chance to see and hear them. I will gradually increase the time they spend out over the next couple of weeks but still bring them in when it cools in the evenings.