If the shutdowns aren't a direct result of heat, it could be a RAM module or hard drive failure (both of these are cheap & easy fixes, though), especially if the components are regularly running hot.

So long as you have the wallet file on the hard drive (and I wouldn't trust that hard drive until the problem's figured out) and it's created the priv-pub key to give you an address to receive at, there's no risk in sending coins to those addresses.