、。
For dehydration, just a lick of salt.
Literal
Dehydration-symptoms [for-には], salt [object-を] one-lick.
A terse health tip in fragment form — no verb, just the noun phrase 塩をひと舐め ('one lick of salt'). 脱水症状 (だっすいしょうじょう, 'dehydration symptoms') is a medical compound. ひと舐め ('one lick') uses the ひと~ prefix ('one / a single') with the verb stem 舐め (from 舐める, to lick). The sentence reads as a quick remedy instruction, like something from a first-aid guide or a grandmother's home remedy.