Is it farther or further?
Old English hedan "to heed, observe; to take care, attend," from West Germanic *hodjan (cf. Old Saxon hodian, Old Frisian hoda, Middle Dutch and Dutch hoeden, Old High German huotan, German hüten "to guard, watch"), from PIE *kadh- "to shelter, cover" (see hat). Related: Heeded; heeding.
"attention, notice, regard," early 14c., apparently from heed (v.). Survives only in literal use and as the object of verbs (take heed, etc.).