These are the super cheap outdoor deals I'm bulk-buying on Amazon Prime Day

Six-month supply hayfever tablets: £3.18 at Amazon
OK, so these aren't actually a special Prime Day deal, but six months of antihistamines for just over £3 is wild. These cost £1.99 per box at Boots, so if cetirizine works for you, they're an absolute steal at Amazon.

HIGH5 Zero Caffeine Hit: £27.95 £19.55 at Amazon
Save £8.40 There are plenty of electrolyte tablets on sale at Amazon for Prime Day, but these are my personal favourites. This is a really good Prime Day deal; this pack of eight tubes (20 tablets each) costs over £30 at Wiggle. 

HIGH5 Energy Gel Aqua: £27.99 £8.75 at Amazon
Save £19.24 These are the energy gels my husband prefers for cycling (I prefer chews personally), and I'll be grabbing this box of 20 sachets on Prime Day. They're currently £13 at Wiggle, for comparison.

Cheeky Panda bamboo tissues (96 packs): £24.99 £17.49 at Amazon
Save £7.50 You know how it is when you're hiking and hayfever strikes, or it's a cold day and your nose decides to start running. Right now, you can get almost 100 packs of hypoallergenic bamboo tissues for under £20, which is cheaper than they've ever been before. You'll never be caught short and snotty again.

Compeed blister plasters: £10.80 £6.02 at Amazon
Save £4.78 No hiking first aid kit would be complete without a pack of these, and you'll pay £4.35 for five if you buy them at Boots, so it's well worth grabbing a few of these 12-packs while they're going cheap for Prime Day.

One year supply of allergy tablets: $7.99 at Amazon
These use a different active ingredient to those listed above (diphenhydramine rather than cetirizine), but if you know that this works for you, this is an incredible deal to keep your allergies under control.

Nuun Sport Electrolyte Tablets: $44.94 $23.77 at Amazon
Save $21.17 I'm a big fan of Nuun electrolyte tabs (they taste a lot better than most), and if you live in the US you can stock up for 47% less than the usual asking price. This deal gives you six flavors, with 10 tablets in each tube (the tropical one is particularly good).

PowerBar PowerGel Original: $42.99 $34.39 at Amazon
Save $8.60 This offer gives you 24 gels for $1.43 each, which is a good cheap way to keep yourself fuelled up during long runs and rides. Wiggle also has them in its summer sale, but Amazon's Prime Day price is better.

Facial tissues (16 packs): $29.99 $23.99 at Amazon
Save $6 I couldn't find an equivalent of Amazon's UK Prime Day deal on bamboo tissues, but this offer is still very respectable, giving you a total of 960 three-ply tissues to tackle snotty noses when you're exploring the great outdoors.

Compeed blister plasters: $20.61 $18.81 at Amazon
Save $1.77 There are larger packs of unbranded blister plasters available more cheaply, but reviews are mixed and some people question the quality of the glue. I can vouch for Compeed, and this deal works out similar to the UK one in terms of price per plaster. You're getting 18 of them here.