Bike helmets

Used to wear a Bern Brentwood helmet religiously (I'm a commuter on a hybrid).   This summer, I gave up and started wearing an Endura urban cycling cap instead.  Feel just as safe, to be honest, and a lot cooler (as in, not hot - I will never be one of the kewl kidz  ).

Anecdata alert: I've come off my bike four times. Twice on black ice; once on a dropped kerb which wasn't as dropped as I would have liked; once involving another vehicle (dooring).  My head has never come anywhere near hitting the ground.  As far as body armour goes, I'd be better advised to start wearing shin pads rather than a helmet.

I bought one of these last weekend.

http://www.decathlon.co.uk/700-road-cycling-helmet-team-colours-id_83546....

It's very light, has lots of crush foam protection, and is very well ventilated. It's comfortable as well. Not bad for 28 quid.

I also have one of these.

A Casco speed time. Unfortunately it did its job, when I crashed a couple of weeks back. A super light aero lid, with lots of decent ventilation, but a massive ball ache, to see over 250 quids worth of lid destroyed:

Pedal slower. You'll only sweat with effort and no helmet is able to prevent sweating.

I tend to pair my helmets with a Sweat GUT'R headband.

This is basically a non-absorbent silicone headband with a literal extruded gutter on the part that goes over your forehead. The thinking is that sweat will collect on the gutter so it doesn't drip into your eyes, flushing toward your temples instead.

The Sweat GUT'R isn't perfect; some sweat does drip into your eyes, but it's noticeably less than if I was riding without it. The fit determines how effective it is - best results are with it rather snug against your forehead. Worth a try at least.

I wear a Lazer with the rolly adjuster thingy on the top. They're OK for the money.

If it's hot and dry I just use a lightweight cycling cap. Take it off and stick in the jersey pocket when I'm deeper into the ride and just stick it on back around town to spare people the wild windblown hair look. Means I don't have to worry about odd tan lines on the face too.

I have a Giro Prolight helmet that's really cool though. Don't think they make those any more. Must weigh about 160g and air flows through it nicely.  

Anything with big open vents. Specialized Prevail worked well for me for years, Cat Like Whisper should be up there and the POC helmets look good.

Cheap helmets tend to have smaller vents and poorer fitting systems so on the assumption that you won't actually need it a more pricey helmet can be a good purchase (plus my Bontrager came with a one year crash replacement policy which is great given my abrupt end to my ride on Saturday...).

I suffer as you.  Just got a MET Sine Thesis from CRC on a close out deal, and BC discount got it to 63 quid (RRP £189).  The key improvement for me is that it uses gel pads rather than pads made from material covered foam.  They don't soak up moisture, so whilst I dont stop sweating, it doesn't store it up in the foam until it eventually gets overwhelmed before dripping in an almost constant flow every time I look down, and onto my glasses.  In this respect the Sine Thesis is better than all my other helmets, although I'd say my Spesh Prevail is a close second due to its excellent venting.