ggbo951a

Already did some online search it appears it usually due to heat. we went AZ trip this summer and it melted bad and very sticky and after ride, black residues are all over my palm. I went to REI the guy pointed me to new grips but he said all has similar melting point considering similar design, composition of materials.
I am just wondering what other options available? Any grips that does not melt at all perhaps up to 150F is fair deal. We went through 116F degree Death Valley trips.
I am thinking about like gloves or some sort of wraps around handles but that is all some extra stuff to carry around in addition to already lot of "stuff" i have.

2_i 

How old were the grips? Soft rubber of the grips eventually deteriorates with age, stains hands, etc. People ride all kinds of bikes at places where >40C temperatures are a plain everyday occurrence, keep their bikes outside and their grips stay fine unless those grips get overly old.

ggbo951a

fairly old, owned the bike for 2-3 years now. pretty sturdy mountain bike except the handle issue described herein.

VegasTriker

You don't mention what type of grips are on your bike. Are they simple grips that slide on and off the handlebars or part of the shift mechanism such as Grip Shifters. You can always use the same type rubber grips or switch to foam grips. Two the three years is not a long time for grips to last before going south. Must be a bad choice on the part of the manufacturer. It was 111 degrees outside yesterday and my bikes and trikes are regularly exposed to those temperatures without doing anything to the grips.
Here is what I have on my Balance 450 MTB https://www.ebay.com/itm/283529802678 $7.43 postpaid. They have been on the bike for at least a couple of years now with no deterioration.

Ogsarg

I've never used them but search for silicone bike grips. Silicone has a high service temp and should be able to handle the worst desert heat.