On the read-only part of the forum there are some informations about Arduino temperature range; apparently it's supposed to work from -40°C to 85°C.
But there are not much precisions about how it fares at high temperatures (50°C and higher); does its lifespan shorten? A lot or juste a little? How do SD connectors/cards, 9V batteries or solar panels, LCD panels, communication modules (Xbee, wifi or ethernet shields) react to high temperatures?
I want to put many sensors inside a solar oven that's supposed not to go over 60°C (emphasis on "supposed"). The safest thing is to put the sensors inside and the Arduino card and shields outside, but while I'm testing the whole system I don't want to drill holes if I can avoid it. That means that I have to use existing holes, and then I have more than four meters between the farthest sensor and the card - I'm not that confident that it won't bring artifacts in the measured values.
So, putting the card inside is a simpler way, but I need to put some storage or communicating device with it - will they too resist to 60°C or more?