A relative speed of 0.1c would make every fully ionised helium atom into an overly wordy description of 18.64 MeV alpha particle radiation.
Low density regions of interstellar medium can have as few as 10e-4 particles per cubic centimetre. At 0.1c, that density works out as 3e10 particles/m^2/s. At that density and energy per particle, 0.0895 W/m^2. Low enough you wouldn’t care.
Molecular clouds, on the other hand, can be up to 10e6 particles/cm^3. Most of those molecules are hydrogen, so they don’t hit as hard on average… but that’s a rounding error compared to the density, so let’s say about half a gigawatt per square meter.
TL;DR — go around the molecular clouds until you invent a Trek-like navigational deflector.
Low density regions of interstellar medium can have as few as 10e-4 particles per cubic centimetre. At 0.1c, that density works out as 3e10 particles/m^2/s. At that density and energy per particle, 0.0895 W/m^2. Low enough you wouldn’t care.
Molecular clouds, on the other hand, can be up to 10e6 particles/cm^3. Most of those molecules are hydrogen, so they don’t hit as hard on average… but that’s a rounding error compared to the density, so let’s say about half a gigawatt per square meter.
TL;DR — go around the molecular clouds until you invent a Trek-like navigational deflector.