Unless you're moving to Venus, there is absolutely no issue with storing your machines in a garage. Temperatures would have to exceed several hundred degrees (more that 300+) to do any damage. Even running computers will tolerate temps in excess of 150. Problems begin to arise as you approach 200 degrees. I ran data centers for the worlds largest computer chip company for years. No harm will come to your machines. Just bring them inside for several hours before plugging them in and using them.