protection against the heat

tight / reliable

be fast, securely in place / be reliable, level-headed / keep going, keep trying

stable, fulfilled

To perform; to do; to conduct oneself; to carry out.

plan, measure, step, countermeasure

fast (in a firm or secure manner), tightly / surely, unwaveringly, steadily, reliably

a budget plan, an economic measure

it is easier said than done

(humble) alternative form of いってきます (itte kimasu)