If your Velcro jacket fasteners were made of this German-engineered steel "Velcro", you'd be able to withstand 35 tons worth of force—provided your skin and bones don't tear first.
The "Velcro", which isn't really Velcro but has one side with spikes and the other with steel brushes, can take heat at up to 800 degrees Celsius, which is plenty sufficient for use in cars, which only gets up to 800 degrees Celsius in direct sunlight.
And if you're interested in tearing these Velcro strips vertically (as in straight out instead of horizontally, where it's stronger), it can hold up to 7 tons. So, a 6 ton man or a 6614 pound Hummer H2 could be suspended from a building with no problem! [New Scientist via Make]