Is temperature fluctuation ok?

[WasabiChicki]

I will be receiving my first mail order day old chick in May! So excited!
I will plan for them to have a lamp for the first two weeks but I'm wondering if my house temp fluctuates between 70 & 80 can I keep the lamp off at that point? I would think it would stay more consistent in the brooder just because they have each other & are moving around most of the time... maybe a lamp just at night for the possibility it gets below 70?
Also, I want to put their brooder outside asap & I'm thinking by three weeks the temp outside shouldn't drop below 75 at all... thats right on tract w/ the -5 degrees each week right?

 

[Egghead_Jr]

As infants and without feathers they are akin to reptiles in that they need a heat source to regulate temperature. You'll need a lamp at all times for first weeks. As your brooding indoors with higher temperatures that lamp could be as low as a 60 or even 40W incandescent. The lamp (I use a metal hood clamp light) should be at one end of brooder (I use a plastic tote) so they can move out from under it if they get too warm.

With a simple thermometer you can check the temp under the light, your shooting for 90 to 95F first few days. Over the course of the weeks your brooding them lower the temp gradually by raising the lamp or lowering the wattage of bulb. In your case that's turning the lamp off days after two weeks since your house temp is 80F daytime. A gradual lowering of 5-7F per week until room temp or after 4 to 5 weeks of feathering is all they need. Depending on outside temperature I've had chicks outside without heat before weeks without heat in coop.

 

[WasabiChicki]

Thank you Egghead...
I was planning to buy a thermometer before the chick arrive & be able to monitor the temp. Will they go into shock or anything if for some reason the lamp went off & temp dropped, say more than 5 degrees overnight? (I'm sure I will be up every hour to check on them lol)
I ask because I am on solar power & have had a couple issues w/ my inverter this last month: one of them being it turning its self off, I think due to the batteries over charging... I plan on this problem being fixed before the chick arrive, but just in case... wondering how much is too much change in the temp...?
Thank you!!