Heedless of time or any other consideration, they began to search the underwater cave. [+ of]

他们顾不上考虑时间或任何其他因素就开始寻找水下洞穴。

She was rummaging through the letters, scattering them about the table in her heedless haste.

她在信件里乱翻，匆忙冒失之下将它们扔得满桌都是。