George Russell completed a positive day for the Silver Arrows with third, the first double podium for the team since the penultimate round of last season.
But describing an issue within the cockpit during a race where air temperatures reached the mid-30 degrees Celsius range, Hamilton said: "That was actually a tough race because my drinks bottle didn't work.
"But what a great result, considering we have been so far off these guys this weekend.
"Reliability is one thing my team has been amazing at so a huge congratulations to the team back at the two factories, the team here who, without them, we couldn't get this podium and George did an amazing job today as well."
On how the malfunctioning drinks bottle affected him, the seven-time champion added: "I didn't see my weight just now but I would imagine [I lost] around three kilos.
"It is enough! I am looking forward to downing the rest of this drink."
Hamilton presses for Hungary upgrades
The Mercedes has shown improved race pace over the past few events with Hamilton and Russell able to at least push Red Bull and Ferrari on Sundays.
On the team's prospects for the Hungarian Grand Prix ahead of the summer break, Hamilton conceded: "It is going to be hard to beat the Ferraris and the Red Bulls, you see they have a pace advantage still.
"I am hoping we will bring some sort of upgrade and take a step closer to them. You can see us in the race, we are able to lean on them a little bit so hopefully, it will be even closer."