Adding salt to water in summer can serve several useful purposes.

Improved Hydration: Salt enhances water absorption in the body by promoting fluid retention.

Taste Enhancement: Some people find that a pinch of salt enhances the taste of water, making it more palatable.

Energy Boost: Proper hydration and electrolyte balance can help maintain energy levels and cognitive function.

Cooling Effect: Saltwater can have a slightly lower freezing point than plain water, which might provide a slightly cooler sensation when consumed.

Electrolyte Balance: Salt helps replenish electrolytes lost through sweat during hot weather, aiding in maintaining hydration.

Prevention of Muscle Cramps: Adding salt to water helps reducing the likelihood of cramping during physical activities in the heat.

Emergency Use: In emergencies where clean water is scarce, adding salt to water can make it safer to drink by disinfecting it to some extent.